Add video_loopback to gn.

BUG=webrtc:5949
NOTRY=True

Review-Url: https://codereview.webrtc.org/2236473002
Cr-Commit-Position: refs/heads/master@{#13748}

webrtc/BUILD.gn

@@ -294,6 +294,35 @@ if (!build_with_chromium) {
       "test",
     ]
   }
+
+  executable("video_loopback") {
+    testonly = true
+    sources = [
+      "test/run_test.h",
+      "video/video_loopback.cc",
+    ]
+
+    if (is_mac) {
+      sources += [ "test/mac/run_test.mm" ]
+    } else {
+      sources += [ "test/run_test.cc" ]
+    }
+    deps = [
+      ":video_quality_test",
+      "system_wrappers:metrics_default",
+      "test:field_trial",
+      "test:test_common",
+      "test:test_renderer",
+      "//testing/gmock",
+      "//testing/gtest",
+      "//third_party/gflags",
+    ]
+    if (is_clang && !is_nacl) {
+      # Suppress warnings from Chrome's Clang plugins.
+      # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
+      configs -= [ "//build/config/clang:find_bad_constructs" ]
+    }
+  }
 }
 
 source_set("webrtc_common") {

webrtc/webrtc_tests.gypi

@@ -277,14 +277,16 @@
       'target_name': 'video_loopback',
       'type': 'executable',
       'sources': [
-        'test/mac/run_test.mm',
-        'test/run_test.cc',
         'test/run_test.h',
         'video/video_loopback.cc',
       ],
       'conditions': [
         ['OS=="mac"', {
-          'sources!': [
+          'sources': [
+            'test/mac/run_test.mm',
+          ],
+        }, {
+          'sources': [
             'test/run_test.cc',
           ],
         }],
@@ -293,10 +295,10 @@
         'video_quality_test',
         '<(DEPTH)/testing/gtest.gyp:gtest',
         '<(DEPTH)/third_party/gflags/gflags.gyp:gflags',
+        '<(webrtc_root)/system_wrappers/system_wrappers.gyp:metrics_default',
+        'test/test.gyp:field_trial',
         'test/test.gyp:test_common',
-        'test/test.gyp:test_main',
         'test/test.gyp:test_renderer',
-        'webrtc',
       ],
     },
     {