diff --git a/BUILD.gn b/BUILD.gn
index 3aa0ae58f7..66b3c52ec2 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -66,6 +66,7 @@ if (!build_with_chromium) {
         "net/dcsctp:dcsctp_unittests",
         "pc:peerconnection_unittests",
         "pc:rtc_pc_unittests",
+        "pc:slow_peer_connection_unittests",
         "rtc_tools:rtp_generator",
         "rtc_tools:video_replay",
         "stats:rtc_stats_unittests",
diff --git a/infra/specs/client.webrtc.json b/infra/specs/client.webrtc.json
index 5df7faa1f7..9d8f620730 100644
--- a/infra/specs/client.webrtc.json
+++ b/infra/specs/client.webrtc.json
@@ -270,8 +270,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -397,6 +396,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -871,8 +900,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -998,6 +1026,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -1230,8 +1288,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -1510,8 +1567,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -1637,6 +1693,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -2111,8 +2197,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -2238,6 +2323,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -2464,8 +2579,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       }
@@ -2642,8 +2756,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -2732,6 +2845,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -3032,8 +3166,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -3122,6 +3255,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -3422,8 +3576,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -3512,6 +3665,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -3812,8 +3986,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -3902,6 +4075,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -4202,8 +4396,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -4292,6 +4485,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -4592,8 +4806,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -4682,6 +4895,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -4983,8 +5217,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -5073,6 +5306,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -5375,8 +5629,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -5465,6 +5718,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -5766,8 +6040,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -5856,6 +6129,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6188,8 +6482,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -6282,6 +6575,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cores": "12",
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6597,8 +6912,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -6691,6 +7005,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cores": "12",
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6997,8 +7333,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7087,6 +7422,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -7417,8 +7773,7 @@
               "os": "Mac",
               "pool": "WebRTC-baremetal"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7511,6 +7866,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "arm64-64-Apple_M1",
+              "os": "Mac",
+              "pool": "WebRTC-baremetal"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -7665,8 +8042,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       }
@@ -7845,8 +8221,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7935,6 +8310,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-7-SP1"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -8257,8 +8653,7 @@
               "cpu": "x86-64",
               "os": "Windows-10-15063"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -8347,6 +8742,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-10-15063"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
diff --git a/infra/specs/gn_isolate_map.pyl b/infra/specs/gn_isolate_map.pyl
index 6446d66410..057e4fe96d 100644
--- a/infra/specs/gn_isolate_map.pyl
+++ b/infra/specs/gn_isolate_map.pyl
@@ -104,6 +104,10 @@
     "label": "//sdk:sdk_unittests",
     "type": "console_test_launcher",
   },
+  "slow_peer_connection_unittests": {
+    "label": "//pc:slow_peer_connection_unittests",
+    "type": "console_test_launcher",
+  },
   "system_wrappers_unittests": {
     "label": "//system_wrappers:system_wrappers_unittests",
     "type": "console_test_launcher",
diff --git a/infra/specs/test_suites.pyl b/infra/specs/test_suites.pyl
index ce153f6f03..e0a3f6df8a 100644
--- a/infra/specs/test_suites.pyl
+++ b/infra/specs/test_suites.pyl
@@ -44,11 +44,7 @@
           'shards': 6
         },
       },
-      'peerconnection_unittests': {
-        'swarming': {
-          'shards': 4
-        },
-      },
+      'peerconnection_unittests': {},
       'rtc_media_unittests': {},
       'rtc_pc_unittests': {},
       'rtc_stats_unittests': {},
@@ -57,6 +53,7 @@
           'shards': 6
         },
       },
+      'slow_peer_connection_unittests': {},
       'system_wrappers_unittests': {},
       'test_support_unittests': {},
       'tools_unittests': {},
@@ -104,11 +101,7 @@
           'shards': 6
         },
       },
-      'peerconnection_unittests': {
-        'swarming': {
-          'shards': 4
-        },
-      },
+      'peerconnection_unittests': {},
       'rtc_media_unittests': {},
       'rtc_pc_unittests': {},
       'rtc_stats_unittests': {},
@@ -117,6 +110,7 @@
           'shards': 6
         },
       },
+      'slow_peer_connection_unittests': {},
       'system_wrappers_unittests': {},
       'test_support_unittests': {},
       'tools_unittests': {},
@@ -229,11 +223,7 @@
       }
     },
     'more_configs_tests': {
-      'peerconnection_unittests': {
-        'swarming': {
-          'shards': 4
-        },
-      },
+      'peerconnection_unittests': {},
     },
     'win_video_capture_tests': {
       'video_capture_tests': {
diff --git a/infra/specs/tryserver.webrtc.json b/infra/specs/tryserver.webrtc.json
index bbafb18299..9c98e37d7f 100644
--- a/infra/specs/tryserver.webrtc.json
+++ b/infra/specs/tryserver.webrtc.json
@@ -270,8 +270,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -397,6 +396,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -905,8 +934,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -1032,6 +1060,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -1540,8 +1598,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -1667,6 +1724,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -1933,8 +2020,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -2210,8 +2296,7 @@
               "device_type": "bullhead",
               "os": "Android"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test": "peerconnection_unittests",
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
@@ -2337,6 +2422,36 @@
         "test": "rtc_unittests",
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_gtest_merge.py"
+        },
+        "resultdb": {
+          "enable": true,
+          "has_native_resultdb_integration": true
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "android_devices": "1",
+              "device_os": "MMB29Q",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ]
+        },
+        "test": "slow_peer_connection_unittests",
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "merge": {
           "args": [],
@@ -5778,8 +5893,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -5868,6 +5982,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6174,8 +6309,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -6264,6 +6398,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6565,8 +6720,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -6655,6 +6809,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -6803,8 +6978,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       }
@@ -6981,8 +7155,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7071,6 +7244,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -7371,8 +7565,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7461,6 +7654,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -7811,8 +8025,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -7901,6 +8114,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -8201,8 +8435,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -8291,6 +8524,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -8591,8 +8845,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -8681,6 +8934,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -8981,8 +9255,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -9071,6 +9344,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -9371,8 +9665,7 @@
               "cpu": "x86-64",
               "os": "Ubuntu-18.04"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -9461,6 +9754,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Ubuntu-18.04"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -9769,8 +10083,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -9863,6 +10176,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cores": "12",
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -10179,8 +10514,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -10273,6 +10607,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cores": "12",
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -10587,8 +10943,7 @@
               "os": "Mac",
               "pool": "WebRTC-baremetal-try"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -10681,6 +11036,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "arm64-64-Apple_M1",
+              "os": "Mac",
+              "pool": "WebRTC-baremetal-try"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -10987,8 +11364,7 @@
               "cpu": "x86-64",
               "os": "Mac-11"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -11077,6 +11453,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Mac-11"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -11435,8 +11832,7 @@
               "os": "Mac",
               "pool": "WebRTC-baremetal-try"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -11529,6 +11925,28 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "arm64-64-Apple_M1",
+              "os": "Mac",
+              "pool": "WebRTC-baremetal-try"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -11835,8 +12253,7 @@
               "cpu": "x86-64",
               "os": "Windows-10-15063"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -11925,6 +12342,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-10-15063"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -12229,8 +12667,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -12319,6 +12756,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-7-SP1"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -12619,8 +13077,7 @@
               "cpu": "x86-64",
               "os": "Windows-10-15063"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -12709,6 +13166,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-10-15063"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -13009,8 +13487,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -13099,6 +13576,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-7-SP1"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -13399,8 +13897,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -13489,6 +13986,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-7-SP1"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -13789,8 +14307,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       },
@@ -13879,6 +14396,27 @@
         },
         "test_id_prefix": "ninja://:rtc_unittests/"
       },
+      {
+        "isolate_name": "slow_peer_connection_unittests",
+        "merge": {
+          "args": [],
+          "script": "//testing/merge_scripts/standard_isolated_script_merge.py"
+        },
+        "name": "slow_peer_connection_unittests",
+        "resultdb": {
+          "result_format": "json"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "os": "Windows-7-SP1"
+            }
+          ]
+        },
+        "test_id_prefix": "ninja://pc:slow_peer_connection_unittests/"
+      },
       {
         "isolate_name": "system_wrappers_unittests",
         "merge": {
@@ -14077,8 +14615,7 @@
               "cpu": "x86-64",
               "os": "Windows-7-SP1"
             }
-          ],
-          "shards": 4
+          ]
         },
         "test_id_prefix": "ninja://pc:peerconnection_unittests/"
       }
diff --git a/pc/BUILD.gn b/pc/BUILD.gn
index 98449a3813..1edbd24502 100644
--- a/pc/BUILD.gn
+++ b/pc/BUILD.gn
@@ -2268,6 +2268,31 @@ if (rtc_include_tests && !build_with_chromium) {
     ]
   }
 
+  rtc_test("slow_peer_connection_unittests") {
+    testonly = true
+    sources = [ "slow_peer_connection_integration_test.cc" ]
+    deps = [
+      ":integration_test_helpers",
+      ":pc_test_utils",
+      "../api:libjingle_peerconnection_api",
+      "../api:scoped_refptr",
+      "../api/units:time_delta",
+      "../p2p:p2p_server_utils",
+      "../p2p:p2p_test_utils",
+      "../p2p:rtc_p2p",
+      "../rtc_base",
+      "../rtc_base:gunit_helpers",
+      "../rtc_base:logging",
+      "../rtc_base:rtc_base_tests_utils",
+      "../rtc_base:socket_address",
+      "../test:test_main",
+      "../test:test_support",
+      "//third_party/abseil-cpp/absl/algorithm:container",
+      "//third_party/abseil-cpp/absl/strings",
+      "//third_party/abseil-cpp/absl/types:optional",
+    ]
+  }
+
   rtc_test("peerconnection_unittests") {
     testonly = true
     sources = [
diff --git a/pc/peer_connection_integrationtest.cc b/pc/peer_connection_integrationtest.cc
index 6017f54dd4..940d7fdc74 100644
--- a/pc/peer_connection_integrationtest.cc
+++ b/pc/peer_connection_integrationtest.cc
@@ -8,17 +8,24 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+// Integration tests for PeerConnection.
+// These tests exercise a full stack over a simulated network.
+//
+// NOTE: If your test takes a while (guideline: more than 5 seconds),
+// do NOT add it here, but instead add it to the file
+// slow_peer_connection_integrationtest.cc
+
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <string>
 #include <tuple>
-#include <type_traits>
 #include <utility>
 #include <vector>
 
 #include "absl/algorithm/container.h"
+#include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 #include "api/async_resolver_factory.h"
 #include "api/candidate.h"
@@ -55,7 +62,6 @@
 #include "p2p/base/port.h"
 #include "p2p/base/port_allocator.h"
 #include "p2p/base/port_interface.h"
-#include "p2p/base/stun_server.h"
 #include "p2p/base/test_stun_server.h"
 #include "p2p/base/test_turn_customizer.h"
 #include "p2p/base/test_turn_server.h"
@@ -615,65 +621,6 @@ TEST_P(PeerConnectionIntegrationTest, AddAudioToVideoOnlyCall) {
   ASSERT_TRUE(ExpectNewFrames(media_expectations));
 }
 
-// This test sets up a call that's transferred to a new caller with a different
-// DTLS fingerprint.
-TEST_P(PeerConnectionIntegrationTest, CallTransferredForCallee) {
-  ASSERT_TRUE(CreatePeerConnectionWrappers());
-  ConnectFakeSignaling();
-  caller()->AddAudioVideoTracks();
-  callee()->AddAudioVideoTracks();
-  caller()->CreateAndSetAndSignalOffer();
-  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
-
-  // Keep the original peer around which will still send packets to the
-  // receiving client. These SRTP packets will be dropped.
-  std::unique_ptr<PeerConnectionIntegrationWrapper> original_peer(
-      SetCallerPcWrapperAndReturnCurrent(
-          CreatePeerConnectionWrapperWithAlternateKey().release()));
-  // TODO(deadbeef): Why do we call Close here? That goes against the comment
-  // directly above.
-  original_peer->pc()->Close();
-
-  ConnectFakeSignaling();
-  caller()->AddAudioVideoTracks();
-  caller()->CreateAndSetAndSignalOffer();
-  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
-  // Wait for some additional frames to be transmitted end-to-end.
-  MediaExpectations media_expectations;
-  media_expectations.ExpectBidirectionalAudioAndVideo();
-  ASSERT_TRUE(ExpectNewFrames(media_expectations));
-}
-
-// This test sets up a call that's transferred to a new callee with a different
-// DTLS fingerprint.
-TEST_P(PeerConnectionIntegrationTest, CallTransferredForCaller) {
-  ASSERT_TRUE(CreatePeerConnectionWrappers());
-  ConnectFakeSignaling();
-  caller()->AddAudioVideoTracks();
-  callee()->AddAudioVideoTracks();
-  caller()->CreateAndSetAndSignalOffer();
-  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
-
-  // Keep the original peer around which will still send packets to the
-  // receiving client. These SRTP packets will be dropped.
-  std::unique_ptr<PeerConnectionIntegrationWrapper> original_peer(
-      SetCalleePcWrapperAndReturnCurrent(
-          CreatePeerConnectionWrapperWithAlternateKey().release()));
-  // TODO(deadbeef): Why do we call Close here? That goes against the comment
-  // directly above.
-  original_peer->pc()->Close();
-
-  ConnectFakeSignaling();
-  callee()->AddAudioVideoTracks();
-  caller()->SetOfferAnswerOptions(IceRestartOfferAnswerOptions());
-  caller()->CreateAndSetAndSignalOffer();
-  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
-  // Wait for some additional frames to be transmitted end-to-end.
-  MediaExpectations media_expectations;
-  media_expectations.ExpectBidirectionalAudioAndVideo();
-  ASSERT_TRUE(ExpectNewFrames(media_expectations));
-}
-
 // This test sets up a non-bundled call and negotiates bundling at the same
 // time as starting an ICE restart. When bundling is in effect in the restart,
 // the DTLS-SRTP context should be successfully reset.
@@ -1361,31 +1308,6 @@ TEST_P(PeerConnectionIntegrationTest, GetBytesSentStatsWithOldStatsApi) {
   EXPECT_GT(caller()->OldGetStatsForTrack(video_track.get())->BytesSent(), 0);
 }
 
-// Test that we can get capture start ntp time.
-TEST_P(PeerConnectionIntegrationTest, GetCaptureStartNtpTimeWithOldStatsApi) {
-  ASSERT_TRUE(CreatePeerConnectionWrappers());
-  ConnectFakeSignaling();
-  caller()->AddAudioTrack();
-
-  callee()->AddAudioTrack();
-
-  // Do offer/answer, wait for the callee to receive some frames.
-  caller()->CreateAndSetAndSignalOffer();
-  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
-
-  // Get the remote audio track created on the receiver, so they can be used as
-  // GetStats filters.
-  auto receivers = callee()->pc()->GetReceivers();
-  ASSERT_EQ(1u, receivers.size());
-  auto remote_audio_track = receivers[0]->track();
-
-  // Get the audio output level stats. Note that the level is not available
-  // until an RTCP packet has been received.
-  EXPECT_TRUE_WAIT(callee()->OldGetStatsForTrack(remote_audio_track.get())
-                           ->CaptureStartNtpTime() > 0,
-                   2 * kMaxWaitForFramesMs);
-}
-
 // Test that the track ID is associated with all local and remote SSRC stats
 // using the old GetStats() and more than 1 audio and more than 1 video track.
 // This is a regression test for crbug.com/906988
@@ -2009,106 +1931,6 @@ class PeerConnectionIntegrationIceStatesTestWithFakeClock
 #if !defined(THREAD_SANITIZER)
 // This test provokes TSAN errors. bugs.webrtc.org/11282
 
-// Tests that the PeerConnection goes through all the ICE gathering/connection
-// states over the duration of the call. This includes Disconnected and Failed
-// states, induced by putting a firewall between the peers and waiting for them
-// to time out.
-TEST_P(PeerConnectionIntegrationIceStatesTestWithFakeClock, VerifyIceStates) {
-  const SocketAddress kStunServerAddress =
-      SocketAddress("99.99.99.1", cricket::STUN_SERVER_PORT);
-  StartStunServer(kStunServerAddress);
-
-  PeerConnectionInterface::RTCConfiguration config;
-  PeerConnectionInterface::IceServer ice_stun_server;
-  ice_stun_server.urls.push_back(
-      "stun:" + kStunServerAddress.HostAsURIString() + ":" +
-      kStunServerAddress.PortAsString());
-  config.servers.push_back(ice_stun_server);
-
-  ASSERT_TRUE(CreatePeerConnectionWrappersWithConfig(config, config));
-  ConnectFakeSignaling();
-  SetPortAllocatorFlags();
-  SetUpNetworkInterfaces();
-  caller()->AddAudioVideoTracks();
-  callee()->AddAudioVideoTracks();
-
-  // Initial state before anything happens.
-  ASSERT_EQ(PeerConnectionInterface::kIceGatheringNew,
-            caller()->ice_gathering_state());
-  ASSERT_EQ(PeerConnectionInterface::kIceConnectionNew,
-            caller()->ice_connection_state());
-  ASSERT_EQ(PeerConnectionInterface::kIceConnectionNew,
-            caller()->standardized_ice_connection_state());
-
-  // Start the call by creating the offer, setting it as the local description,
-  // then sending it to the peer who will respond with an answer. This happens
-  // asynchronously so that we can watch the states as it runs in the
-  // background.
-  caller()->CreateAndSetAndSignalOffer();
-
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
-                           caller()->ice_connection_state(), kDefaultTimeout,
-                           FakeClock());
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
-                           caller()->standardized_ice_connection_state(),
-                           kDefaultTimeout, FakeClock());
-
-  // Verify that the observer was notified of the intermediate transitions.
-  EXPECT_THAT(caller()->ice_connection_state_history(),
-              ElementsAre(PeerConnectionInterface::kIceConnectionChecking,
-                          PeerConnectionInterface::kIceConnectionConnected,
-                          PeerConnectionInterface::kIceConnectionCompleted));
-  EXPECT_THAT(caller()->standardized_ice_connection_state_history(),
-              ElementsAre(PeerConnectionInterface::kIceConnectionChecking,
-                          PeerConnectionInterface::kIceConnectionConnected,
-                          PeerConnectionInterface::kIceConnectionCompleted));
-  EXPECT_THAT(
-      caller()->peer_connection_state_history(),
-      ElementsAre(PeerConnectionInterface::PeerConnectionState::kConnecting,
-                  PeerConnectionInterface::PeerConnectionState::kConnected));
-  EXPECT_THAT(caller()->ice_gathering_state_history(),
-              ElementsAre(PeerConnectionInterface::kIceGatheringGathering,
-                          PeerConnectionInterface::kIceGatheringComplete));
-
-  // Block connections to/from the caller and wait for ICE to become
-  // disconnected.
-  for (const auto& caller_address : CallerAddresses()) {
-    firewall()->AddRule(false, rtc::FP_ANY, rtc::FD_ANY, caller_address);
-  }
-  RTC_LOG(LS_INFO) << "Firewall rules applied";
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionDisconnected,
-                           caller()->ice_connection_state(), kDefaultTimeout,
-                           FakeClock());
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionDisconnected,
-                           caller()->standardized_ice_connection_state(),
-                           kDefaultTimeout, FakeClock());
-
-  // Let ICE re-establish by removing the firewall rules.
-  firewall()->ClearRules();
-  RTC_LOG(LS_INFO) << "Firewall rules cleared";
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
-                           caller()->ice_connection_state(), kDefaultTimeout,
-                           FakeClock());
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
-                           caller()->standardized_ice_connection_state(),
-                           kDefaultTimeout, FakeClock());
-
-  // According to RFC7675, if there is no response within 30 seconds then the
-  // peer should consider the other side to have rejected the connection. This
-  // is signaled by the state transitioning to "failed".
-  constexpr int kConsentTimeout = 30000;
-  for (const auto& caller_address : CallerAddresses()) {
-    firewall()->AddRule(false, rtc::FP_ANY, rtc::FD_ANY, caller_address);
-  }
-  RTC_LOG(LS_INFO) << "Firewall rules applied again";
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionFailed,
-                           caller()->ice_connection_state(), kConsentTimeout,
-                           FakeClock());
-  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionFailed,
-                           caller()->standardized_ice_connection_state(),
-                           kConsentTimeout, FakeClock());
-}
-
 // Tests that if the connection doesn't get set up properly we eventually reach
 // the "failed" iceConnectionState.
 TEST_P(PeerConnectionIntegrationIceStatesTestWithFakeClock,
@@ -2770,71 +2592,6 @@ TEST_P(PeerConnectionIntegrationTest,
   EXPECT_GT(client_2_cert_verifier->call_count_, 0u);
 }
 
-TEST_P(PeerConnectionIntegrationTest,
-       SSLCertificateVerifierFailureUsedForTurnConnectionsFailsConnection) {
-  static const rtc::SocketAddress turn_server_internal_address{"88.88.88.0",
-                                                               3478};
-  static const rtc::SocketAddress turn_server_external_address{"88.88.88.1", 0};
-
-  // Enable TCP-TLS for the fake turn server. We need to pass in 88.88.88.0 so
-  // that host name verification passes on the fake certificate.
-  CreateTurnServer(turn_server_internal_address, turn_server_external_address,
-                   cricket::PROTO_TLS, "88.88.88.0");
-
-  webrtc::PeerConnectionInterface::IceServer ice_server;
-  ice_server.urls.push_back("turns:88.88.88.0:3478?transport=tcp");
-  ice_server.username = "test";
-  ice_server.password = "test";
-
-  PeerConnectionInterface::RTCConfiguration client_1_config;
-  client_1_config.servers.push_back(ice_server);
-  client_1_config.type = webrtc::PeerConnectionInterface::kRelay;
-
-  PeerConnectionInterface::RTCConfiguration client_2_config;
-  client_2_config.servers.push_back(ice_server);
-  // Setting the type to kRelay forces the connection to go through a TURN
-  // server.
-  client_2_config.type = webrtc::PeerConnectionInterface::kRelay;
-
-  // Get a copy to the pointer so we can verify calls later.
-  rtc::TestCertificateVerifier* client_1_cert_verifier =
-      new rtc::TestCertificateVerifier();
-  client_1_cert_verifier->verify_certificate_ = false;
-  rtc::TestCertificateVerifier* client_2_cert_verifier =
-      new rtc::TestCertificateVerifier();
-  client_2_cert_verifier->verify_certificate_ = false;
-
-  // Create the dependencies with the test certificate verifier.
-  webrtc::PeerConnectionDependencies client_1_deps(nullptr);
-  client_1_deps.tls_cert_verifier =
-      std::unique_ptr<rtc::TestCertificateVerifier>(client_1_cert_verifier);
-  webrtc::PeerConnectionDependencies client_2_deps(nullptr);
-  client_2_deps.tls_cert_verifier =
-      std::unique_ptr<rtc::TestCertificateVerifier>(client_2_cert_verifier);
-
-  ASSERT_TRUE(CreatePeerConnectionWrappersWithConfigAndDeps(
-      client_1_config, std::move(client_1_deps), client_2_config,
-      std::move(client_2_deps)));
-  ConnectFakeSignaling();
-
-  // Set "offer to receive audio/video" without adding any tracks, so we just
-  // set up ICE/DTLS with no media.
-  PeerConnectionInterface::RTCOfferAnswerOptions options;
-  options.offer_to_receive_audio = 1;
-  options.offer_to_receive_video = 1;
-  caller()->SetOfferAnswerOptions(options);
-  caller()->CreateAndSetAndSignalOffer();
-  bool wait_res = true;
-  // TODO(bugs.webrtc.org/9219): When IceConnectionState is implemented
-  // properly, should be able to just wait for a state of "failed" instead of
-  // waiting a fixed 10 seconds.
-  WAIT_(DtlsConnected(), kDefaultTimeout, wait_res);
-  ASSERT_FALSE(wait_res);
-
-  EXPECT_GT(client_1_cert_verifier->call_count_, 0u);
-  EXPECT_GT(client_2_cert_verifier->call_count_, 0u);
-}
-
 // Test that the injected ICE transport factory is used to create ICE transports
 // for WebRTC connections.
 TEST_P(PeerConnectionIntegrationTest, IceTransportFactoryUsedForConnections) {
diff --git a/pc/slow_peer_connection_integration_test.cc b/pc/slow_peer_connection_integration_test.cc
new file mode 100644
index 0000000000..b45571ec22
--- /dev/null
+++ b/pc/slow_peer_connection_integration_test.cc
@@ -0,0 +1,512 @@
+/*
+ *  Copyright 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// This file is intended for PeerConnection integration tests that are
+// slow to execute (currently defined as more than 5 seconds per test).
+
+#include <stdint.h>
+
+#include <memory>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+#include "absl/algorithm/container.h"
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "api/dtmf_sender_interface.h"
+#include "api/peer_connection_interface.h"
+#include "api/rtp_receiver_interface.h"
+#include "api/scoped_refptr.h"
+#include "api/units/time_delta.h"
+#include "p2p/base/port_allocator.h"
+#include "p2p/base/port_interface.h"
+#include "p2p/base/stun_server.h"
+#include "p2p/base/test_stun_server.h"
+#include "pc/test/integration_test_helpers.h"
+#include "pc/test/mock_peer_connection_observers.h"
+#include "rtc_base/fake_clock.h"
+#include "rtc_base/fake_network.h"
+#include "rtc_base/firewall_socket_server.h"
+#include "rtc_base/gunit.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/ssl_certificate.h"
+#include "rtc_base/test_certificate_verifier.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+
+class PeerConnectionIntegrationTest
+    : public PeerConnectionIntegrationBaseTest,
+      public ::testing::WithParamInterface<
+          std::tuple<SdpSemantics, std::string>> {
+ protected:
+  PeerConnectionIntegrationTest()
+      : PeerConnectionIntegrationBaseTest(std::get<0>(GetParam()),
+                                          std::get<1>(GetParam())) {}
+};
+
+// Fake clock must be set before threads are started to prevent race on
+// Set/GetClockForTesting().
+// To achieve that, multiple inheritance is used as a mixin pattern
+// where order of construction is finely controlled.
+// This also ensures peerconnection is closed before switching back to non-fake
+// clock, avoiding other races and DCHECK failures such as in rtp_sender.cc.
+class FakeClockForTest : public rtc::ScopedFakeClock {
+ protected:
+  FakeClockForTest() {
+    // Some things use a time of "0" as a special value, so we need to start out
+    // the fake clock at a nonzero time.
+    // TODO(deadbeef): Fix this.
+    AdvanceTime(webrtc::TimeDelta::Seconds(1));
+  }
+
+  // Explicit handle.
+  ScopedFakeClock& FakeClock() { return *this; }
+};
+
+// Ensure FakeClockForTest is constructed first (see class for rationale).
+class PeerConnectionIntegrationTestWithFakeClock
+    : public FakeClockForTest,
+      public PeerConnectionIntegrationTest {};
+
+class PeerConnectionIntegrationTestPlanB
+    : public PeerConnectionIntegrationBaseTest {
+ protected:
+  PeerConnectionIntegrationTestPlanB()
+      : PeerConnectionIntegrationBaseTest(SdpSemantics::kPlanB_DEPRECATED) {}
+};
+
+class PeerConnectionIntegrationTestUnifiedPlan
+    : public PeerConnectionIntegrationBaseTest {
+ protected:
+  PeerConnectionIntegrationTestUnifiedPlan()
+      : PeerConnectionIntegrationBaseTest(SdpSemantics::kUnifiedPlan) {}
+};
+
+// Test the OnFirstPacketReceived callback from audio/video RtpReceivers.  This
+// includes testing that the callback is invoked if an observer is connected
+// after the first packet has already been received.
+TEST_P(PeerConnectionIntegrationTest,
+       RtpReceiverObserverOnFirstPacketReceived) {
+  ASSERT_TRUE(CreatePeerConnectionWrappers());
+  ConnectFakeSignaling();
+  caller()->AddAudioVideoTracks();
+  callee()->AddAudioVideoTracks();
+  // Start offer/answer exchange and wait for it to complete.
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+  // Should be one receiver each for audio/video.
+  EXPECT_EQ(2U, caller()->rtp_receiver_observers().size());
+  EXPECT_EQ(2U, callee()->rtp_receiver_observers().size());
+  // Wait for all "first packet received" callbacks to be fired.
+  EXPECT_TRUE_WAIT(
+      absl::c_all_of(caller()->rtp_receiver_observers(),
+                     [](const std::unique_ptr<MockRtpReceiverObserver>& o) {
+                       return o->first_packet_received();
+                     }),
+      kMaxWaitForFramesMs);
+  EXPECT_TRUE_WAIT(
+      absl::c_all_of(callee()->rtp_receiver_observers(),
+                     [](const std::unique_ptr<MockRtpReceiverObserver>& o) {
+                       return o->first_packet_received();
+                     }),
+      kMaxWaitForFramesMs);
+  // If new observers are set after the first packet was already received, the
+  // callback should still be invoked.
+  caller()->ResetRtpReceiverObservers();
+  callee()->ResetRtpReceiverObservers();
+  EXPECT_EQ(2U, caller()->rtp_receiver_observers().size());
+  EXPECT_EQ(2U, callee()->rtp_receiver_observers().size());
+  EXPECT_TRUE(
+      absl::c_all_of(caller()->rtp_receiver_observers(),
+                     [](const std::unique_ptr<MockRtpReceiverObserver>& o) {
+                       return o->first_packet_received();
+                     }));
+  EXPECT_TRUE(
+      absl::c_all_of(callee()->rtp_receiver_observers(),
+                     [](const std::unique_ptr<MockRtpReceiverObserver>& o) {
+                       return o->first_packet_received();
+                     }));
+}
+
+class DummyDtmfObserver : public DtmfSenderObserverInterface {
+ public:
+  DummyDtmfObserver() : completed_(false) {}
+
+  // Implements DtmfSenderObserverInterface.
+  void OnToneChange(const std::string& tone) override {
+    tones_.push_back(tone);
+    if (tone.empty()) {
+      completed_ = true;
+    }
+  }
+
+  const std::vector<std::string>& tones() const { return tones_; }
+  bool completed() const { return completed_; }
+
+ private:
+  bool completed_;
+  std::vector<std::string> tones_;
+};
+
+TEST_P(PeerConnectionIntegrationTest,
+       SSLCertificateVerifierFailureUsedForTurnConnectionsFailsConnection) {
+  static const rtc::SocketAddress turn_server_internal_address{"88.88.88.0",
+                                                               3478};
+  static const rtc::SocketAddress turn_server_external_address{"88.88.88.1", 0};
+
+  // Enable TCP-TLS for the fake turn server. We need to pass in 88.88.88.0 so
+  // that host name verification passes on the fake certificate.
+  CreateTurnServer(turn_server_internal_address, turn_server_external_address,
+                   cricket::PROTO_TLS, "88.88.88.0");
+
+  webrtc::PeerConnectionInterface::IceServer ice_server;
+  ice_server.urls.push_back("turns:88.88.88.0:3478?transport=tcp");
+  ice_server.username = "test";
+  ice_server.password = "test";
+
+  PeerConnectionInterface::RTCConfiguration client_1_config;
+  client_1_config.servers.push_back(ice_server);
+  client_1_config.type = webrtc::PeerConnectionInterface::kRelay;
+
+  PeerConnectionInterface::RTCConfiguration client_2_config;
+  client_2_config.servers.push_back(ice_server);
+  // Setting the type to kRelay forces the connection to go through a TURN
+  // server.
+  client_2_config.type = webrtc::PeerConnectionInterface::kRelay;
+
+  // Get a copy to the pointer so we can verify calls later.
+  rtc::TestCertificateVerifier* client_1_cert_verifier =
+      new rtc::TestCertificateVerifier();
+  client_1_cert_verifier->verify_certificate_ = false;
+  rtc::TestCertificateVerifier* client_2_cert_verifier =
+      new rtc::TestCertificateVerifier();
+  client_2_cert_verifier->verify_certificate_ = false;
+
+  // Create the dependencies with the test certificate verifier.
+  webrtc::PeerConnectionDependencies client_1_deps(nullptr);
+  client_1_deps.tls_cert_verifier =
+      std::unique_ptr<rtc::TestCertificateVerifier>(client_1_cert_verifier);
+  webrtc::PeerConnectionDependencies client_2_deps(nullptr);
+  client_2_deps.tls_cert_verifier =
+      std::unique_ptr<rtc::TestCertificateVerifier>(client_2_cert_verifier);
+
+  ASSERT_TRUE(CreatePeerConnectionWrappersWithConfigAndDeps(
+      client_1_config, std::move(client_1_deps), client_2_config,
+      std::move(client_2_deps)));
+  ConnectFakeSignaling();
+
+  // Set "offer to receive audio/video" without adding any tracks, so we just
+  // set up ICE/DTLS with no media.
+  PeerConnectionInterface::RTCOfferAnswerOptions options;
+  options.offer_to_receive_audio = 1;
+  options.offer_to_receive_video = 1;
+  caller()->SetOfferAnswerOptions(options);
+  caller()->CreateAndSetAndSignalOffer();
+  bool wait_res = true;
+  // TODO(bugs.webrtc.org/9219): When IceConnectionState is implemented
+  // properly, should be able to just wait for a state of "failed" instead of
+  // waiting a fixed 10 seconds.
+  WAIT_(DtlsConnected(), kDefaultTimeout, wait_res);
+  ASSERT_FALSE(wait_res);
+
+  EXPECT_GT(client_1_cert_verifier->call_count_, 0u);
+  EXPECT_GT(client_2_cert_verifier->call_count_, 0u);
+}
+
+// Test that we can get capture start ntp time.
+TEST_P(PeerConnectionIntegrationTest, GetCaptureStartNtpTimeWithOldStatsApi) {
+  ASSERT_TRUE(CreatePeerConnectionWrappers());
+  ConnectFakeSignaling();
+  caller()->AddAudioTrack();
+
+  callee()->AddAudioTrack();
+
+  // Do offer/answer, wait for the callee to receive some frames.
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+
+  // Get the remote audio track created on the receiver, so they can be used as
+  // GetStats filters.
+  auto receivers = callee()->pc()->GetReceivers();
+  ASSERT_EQ(1u, receivers.size());
+  auto remote_audio_track = receivers[0]->track();
+
+  // Get the audio output level stats. Note that the level is not available
+  // until an RTCP packet has been received.
+  EXPECT_TRUE_WAIT(callee()->OldGetStatsForTrack(remote_audio_track.get())
+                           ->CaptureStartNtpTime() > 0,
+                   2 * kMaxWaitForFramesMs);
+}
+
+// Test that firewalling the ICE connection causes the clients to identify the
+// disconnected state and then removing the firewall causes them to reconnect.
+class PeerConnectionIntegrationIceStatesTest
+    : public PeerConnectionIntegrationBaseTest,
+      public ::testing::WithParamInterface<
+          std::tuple<SdpSemantics, std::tuple<std::string, uint32_t>>> {
+ protected:
+  PeerConnectionIntegrationIceStatesTest()
+      : PeerConnectionIntegrationBaseTest(std::get<0>(GetParam())) {
+    port_allocator_flags_ = std::get<1>(std::get<1>(GetParam()));
+  }
+
+  void StartStunServer(const SocketAddress& server_address) {
+    stun_server_.reset(
+        cricket::TestStunServer::Create(firewall(), server_address));
+  }
+
+  bool TestIPv6() {
+    return (port_allocator_flags_ & cricket::PORTALLOCATOR_ENABLE_IPV6);
+  }
+
+  void SetPortAllocatorFlags() {
+    PeerConnectionIntegrationBaseTest::SetPortAllocatorFlags(
+        port_allocator_flags_, port_allocator_flags_);
+  }
+
+  std::vector<SocketAddress> CallerAddresses() {
+    std::vector<SocketAddress> addresses;
+    addresses.push_back(SocketAddress("1.1.1.1", 0));
+    if (TestIPv6()) {
+      addresses.push_back(SocketAddress("1111:0:a:b:c:d:e:f", 0));
+    }
+    return addresses;
+  }
+
+  std::vector<SocketAddress> CalleeAddresses() {
+    std::vector<SocketAddress> addresses;
+    addresses.push_back(SocketAddress("2.2.2.2", 0));
+    if (TestIPv6()) {
+      addresses.push_back(SocketAddress("2222:0:a:b:c:d:e:f", 0));
+    }
+    return addresses;
+  }
+
+  void SetUpNetworkInterfaces() {
+    // Remove the default interfaces added by the test infrastructure.
+    caller()->network_manager()->RemoveInterface(kDefaultLocalAddress);
+    callee()->network_manager()->RemoveInterface(kDefaultLocalAddress);
+
+    // Add network addresses for test.
+    for (const auto& caller_address : CallerAddresses()) {
+      caller()->network_manager()->AddInterface(caller_address);
+    }
+    for (const auto& callee_address : CalleeAddresses()) {
+      callee()->network_manager()->AddInterface(callee_address);
+    }
+  }
+
+ private:
+  uint32_t port_allocator_flags_;
+  std::unique_ptr<cricket::TestStunServer> stun_server_;
+};
+
+// Ensure FakeClockForTest is constructed first (see class for rationale).
+class PeerConnectionIntegrationIceStatesTestWithFakeClock
+    : public FakeClockForTest,
+      public PeerConnectionIntegrationIceStatesTest {};
+
+#if !defined(THREAD_SANITIZER)
+// This test provokes TSAN errors. bugs.webrtc.org/11282
+
+// Tests that the PeerConnection goes through all the ICE gathering/connection
+// states over the duration of the call. This includes Disconnected and Failed
+// states, induced by putting a firewall between the peers and waiting for them
+// to time out.
+TEST_P(PeerConnectionIntegrationIceStatesTestWithFakeClock, VerifyIceStates) {
+  const SocketAddress kStunServerAddress =
+      SocketAddress("99.99.99.1", cricket::STUN_SERVER_PORT);
+  StartStunServer(kStunServerAddress);
+
+  PeerConnectionInterface::RTCConfiguration config;
+  PeerConnectionInterface::IceServer ice_stun_server;
+  ice_stun_server.urls.push_back(
+      "stun:" + kStunServerAddress.HostAsURIString() + ":" +
+      kStunServerAddress.PortAsString());
+  config.servers.push_back(ice_stun_server);
+
+  ASSERT_TRUE(CreatePeerConnectionWrappersWithConfig(config, config));
+  ConnectFakeSignaling();
+  SetPortAllocatorFlags();
+  SetUpNetworkInterfaces();
+  caller()->AddAudioVideoTracks();
+  callee()->AddAudioVideoTracks();
+
+  // Initial state before anything happens.
+  ASSERT_EQ(PeerConnectionInterface::kIceGatheringNew,
+            caller()->ice_gathering_state());
+  ASSERT_EQ(PeerConnectionInterface::kIceConnectionNew,
+            caller()->ice_connection_state());
+  ASSERT_EQ(PeerConnectionInterface::kIceConnectionNew,
+            caller()->standardized_ice_connection_state());
+
+  // Start the call by creating the offer, setting it as the local description,
+  // then sending it to the peer who will respond with an answer. This happens
+  // asynchronously so that we can watch the states as it runs in the
+  // background.
+  caller()->CreateAndSetAndSignalOffer();
+
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
+                           caller()->ice_connection_state(), kDefaultTimeout,
+                           FakeClock());
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
+                           caller()->standardized_ice_connection_state(),
+                           kDefaultTimeout, FakeClock());
+
+  // Verify that the observer was notified of the intermediate transitions.
+  EXPECT_THAT(caller()->ice_connection_state_history(),
+              ElementsAre(PeerConnectionInterface::kIceConnectionChecking,
+                          PeerConnectionInterface::kIceConnectionConnected,
+                          PeerConnectionInterface::kIceConnectionCompleted));
+  EXPECT_THAT(caller()->standardized_ice_connection_state_history(),
+              ElementsAre(PeerConnectionInterface::kIceConnectionChecking,
+                          PeerConnectionInterface::kIceConnectionConnected,
+                          PeerConnectionInterface::kIceConnectionCompleted));
+  EXPECT_THAT(
+      caller()->peer_connection_state_history(),
+      ElementsAre(PeerConnectionInterface::PeerConnectionState::kConnecting,
+                  PeerConnectionInterface::PeerConnectionState::kConnected));
+  EXPECT_THAT(caller()->ice_gathering_state_history(),
+              ElementsAre(PeerConnectionInterface::kIceGatheringGathering,
+                          PeerConnectionInterface::kIceGatheringComplete));
+
+  // Block connections to/from the caller and wait for ICE to become
+  // disconnected.
+  for (const auto& caller_address : CallerAddresses()) {
+    firewall()->AddRule(false, rtc::FP_ANY, rtc::FD_ANY, caller_address);
+  }
+  RTC_LOG(LS_INFO) << "Firewall rules applied";
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionDisconnected,
+                           caller()->ice_connection_state(), kDefaultTimeout,
+                           FakeClock());
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionDisconnected,
+                           caller()->standardized_ice_connection_state(),
+                           kDefaultTimeout, FakeClock());
+
+  // Let ICE re-establish by removing the firewall rules.
+  firewall()->ClearRules();
+  RTC_LOG(LS_INFO) << "Firewall rules cleared";
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
+                           caller()->ice_connection_state(), kDefaultTimeout,
+                           FakeClock());
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionCompleted,
+                           caller()->standardized_ice_connection_state(),
+                           kDefaultTimeout, FakeClock());
+
+  // According to RFC7675, if there is no response within 30 seconds then the
+  // peer should consider the other side to have rejected the connection. This
+  // is signaled by the state transitioning to "failed".
+  constexpr int kConsentTimeout = 30000;
+  for (const auto& caller_address : CallerAddresses()) {
+    firewall()->AddRule(false, rtc::FP_ANY, rtc::FD_ANY, caller_address);
+  }
+  RTC_LOG(LS_INFO) << "Firewall rules applied again";
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionFailed,
+                           caller()->ice_connection_state(), kConsentTimeout,
+                           FakeClock());
+  ASSERT_EQ_SIMULATED_WAIT(PeerConnectionInterface::kIceConnectionFailed,
+                           caller()->standardized_ice_connection_state(),
+                           kConsentTimeout, FakeClock());
+}
+#endif
+
+// This test sets up a call that's transferred to a new caller with a different
+// DTLS fingerprint.
+TEST_P(PeerConnectionIntegrationTest, CallTransferredForCallee) {
+  ASSERT_TRUE(CreatePeerConnectionWrappers());
+  ConnectFakeSignaling();
+  caller()->AddAudioVideoTracks();
+  callee()->AddAudioVideoTracks();
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+
+  // Keep the original peer around which will still send packets to the
+  // receiving client. These SRTP packets will be dropped.
+  std::unique_ptr<PeerConnectionIntegrationWrapper> original_peer(
+      SetCallerPcWrapperAndReturnCurrent(
+          CreatePeerConnectionWrapperWithAlternateKey().release()));
+  // TODO(deadbeef): Why do we call Close here? That goes against the comment
+  // directly above.
+  original_peer->pc()->Close();
+
+  ConnectFakeSignaling();
+  caller()->AddAudioVideoTracks();
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+  // Wait for some additional frames to be transmitted end-to-end.
+  MediaExpectations media_expectations;
+  media_expectations.ExpectBidirectionalAudioAndVideo();
+  ASSERT_TRUE(ExpectNewFrames(media_expectations));
+}
+
+// This test sets up a call that's transferred to a new callee with a different
+// DTLS fingerprint.
+TEST_P(PeerConnectionIntegrationTest, CallTransferredForCaller) {
+  ASSERT_TRUE(CreatePeerConnectionWrappers());
+  ConnectFakeSignaling();
+  caller()->AddAudioVideoTracks();
+  callee()->AddAudioVideoTracks();
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+
+  // Keep the original peer around which will still send packets to the
+  // receiving client. These SRTP packets will be dropped.
+  std::unique_ptr<PeerConnectionIntegrationWrapper> original_peer(
+      SetCalleePcWrapperAndReturnCurrent(
+          CreatePeerConnectionWrapperWithAlternateKey().release()));
+  // TODO(deadbeef): Why do we call Close here? That goes against the comment
+  // directly above.
+  original_peer->pc()->Close();
+
+  ConnectFakeSignaling();
+  callee()->AddAudioVideoTracks();
+  caller()->SetOfferAnswerOptions(IceRestartOfferAnswerOptions());
+  caller()->CreateAndSetAndSignalOffer();
+  ASSERT_TRUE_WAIT(SignalingStateStable(), kDefaultTimeout);
+  // Wait for some additional frames to be transmitted end-to-end.
+  MediaExpectations media_expectations;
+  media_expectations.ExpectBidirectionalAudioAndVideo();
+  ASSERT_TRUE(ExpectNewFrames(media_expectations));
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    PeerConnectionIntegrationTest,
+    PeerConnectionIntegrationTest,
+    Combine(Values(SdpSemantics::kPlanB_DEPRECATED, SdpSemantics::kUnifiedPlan),
+            Values("WebRTC-FrameBuffer3/arm:FrameBuffer2/",
+                   "WebRTC-FrameBuffer3/arm:FrameBuffer3/",
+                   "WebRTC-FrameBuffer3/arm:SyncDecoding/")));
+
+constexpr uint32_t kFlagsIPv4NoStun = cricket::PORTALLOCATOR_DISABLE_TCP |
+                                      cricket::PORTALLOCATOR_DISABLE_STUN |
+                                      cricket::PORTALLOCATOR_DISABLE_RELAY;
+constexpr uint32_t kFlagsIPv6NoStun =
+    cricket::PORTALLOCATOR_DISABLE_TCP | cricket::PORTALLOCATOR_DISABLE_STUN |
+    cricket::PORTALLOCATOR_ENABLE_IPV6 | cricket::PORTALLOCATOR_DISABLE_RELAY;
+constexpr uint32_t kFlagsIPv4Stun =
+    cricket::PORTALLOCATOR_DISABLE_TCP | cricket::PORTALLOCATOR_DISABLE_RELAY;
+
+INSTANTIATE_TEST_SUITE_P(
+    PeerConnectionIntegrationTest,
+    PeerConnectionIntegrationIceStatesTestWithFakeClock,
+    Combine(Values(SdpSemantics::kPlanB_DEPRECATED, SdpSemantics::kUnifiedPlan),
+            Values(std::make_pair("IPv4 no STUN", kFlagsIPv4NoStun),
+                   std::make_pair("IPv6 no STUN", kFlagsIPv6NoStun),
+                   std::make_pair("IPv4 with STUN", kFlagsIPv4Stun))));
+
+}  // namespace
+}  // namespace webrtc