Add rtc_common_public_deps

When built for chromium, some webrtc implementations are overridden and
are implemented by chrome's "//base". For instance webrtc::Location is
implemented by base::Location. So far so good, the affected targets are
correctly defined in GN to depend on base.

The problem: Most targets in webrtc do not declare correctly their
public_deps. When a public header of a target includes one from its
dependency, the dependency must be a public_deps. The public_deps
instruct GN to forward the capability to use code from the dependency
toward the dependent.

Unfortunately, it is not possible to fix the `public_deps` in webrtc,
because its is disallowed via a presubmit. See:
https://webrtc-review.googlesource.com/c/src/+/30262

WebRTC developers decided not to use `public_deps`, because GN config
are "translated" toward different kind of downstream build system who do
not really support the `public` dependencies concept. Instead WebRTC is
using some "common" configuration applied to all of its targets.

This patch add `rtc_common_public_deps` argument, to let embedders
add the dependencies WebRTC depends on.

Bug: chromium:1467773
Change-Id: I7de43372414a09886fcb07905451e6339c8ecc64
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/316660
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40595}

api/BUILD.gn

@@ -268,7 +268,7 @@ rtc_library("libjingle_peerconnection_api") {
     "dtmf_sender_interface.h",
     "rtp_sender_interface.h",
   ]
-  public_deps = [  # no-presubmit-check TODO(webrtc:8603)
+  public_deps += [  # no-presubmit-check TODO(webrtc:8603)
     # Remove when downstream has been updated
     ":dtmf_sender_interface",
     ":rtp_sender_interface",

modules/audio_coding/BUILD.gn

@@ -155,7 +155,7 @@ rtc_library("g711") {
     "../../rtc_base:checks",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
-  public_deps = [ ":g711_c" ]  # no-presubmit-check TODO(webrtc:8603)
+  public_deps += [ ":g711_c" ]  # no-presubmit-check TODO(webrtc:8603)
 }
 
 rtc_library("g711_c") {
@@ -188,7 +188,7 @@ rtc_library("g722") {
     "../../rtc_base:safe_conversions",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
-  public_deps = [ ":g722_c" ]  # no-presubmit-check TODO(webrtc:8603)
+  public_deps += [ ":g722_c" ]  # no-presubmit-check TODO(webrtc:8603)
 }
 
 rtc_library("g722_c") {
@@ -223,7 +223,7 @@ rtc_library("ilbc") {
     "../../rtc_base:safe_conversions",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
-  public_deps = [ ":ilbc_c" ]  # no-presubmit-check TODO(webrtc:8603)
+  public_deps += [ ":ilbc_c" ]  # no-presubmit-check TODO(webrtc:8603)
 }
 
 rtc_library("ilbc_c") {
@@ -430,7 +430,7 @@ rtc_library("pcm16b") {
     "../../rtc_base:buffer",
     "../../rtc_base:checks",
   ]
-  public_deps = [ ":pcm16b_c" ]  # no-presubmit-check TODO(webrtc:8603)
+  public_deps += [ ":pcm16b_c" ]  # no-presubmit-check TODO(webrtc:8603)
 }
 
 rtc_library("pcm16b_c") {
@@ -492,7 +492,7 @@ rtc_library("webrtc_opus") {
     "//third_party/abseil-cpp/absl/strings",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
-  public_deps =  # no-presubmit-check TODO(webrtc:8603)
+  public_deps +=  # no-presubmit-check TODO(webrtc:8603)
       [ ":webrtc_opus_wrapper" ]
 
   defines = audio_codec_defines
@@ -526,7 +526,7 @@ rtc_library("webrtc_multiopus") {
     "//third_party/abseil-cpp/absl/strings",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
-  public_deps =  # no-presubmit-check TODO(webrtc:8603)
+  public_deps +=  # no-presubmit-check TODO(webrtc:8603)
       [ ":webrtc_opus_wrapper" ]
 
   defines = audio_codec_defines
@@ -609,7 +609,7 @@ rtc_library("audio_network_adaptor") {
     "audio_network_adaptor/util/threshold_curve.h",
   ]
 
-  public_deps =  # no-presubmit-check TODO(webrtc:8603)
+  public_deps +=  # no-presubmit-check TODO(webrtc:8603)
       [ ":audio_network_adaptor_config" ]
 
   deps = [
@@ -892,7 +892,7 @@ rtc_library("neteq_tools") {
       "neteq/tools/neteq_event_log_input.h",
     ]
     deps += [ "../../logging:rtc_event_log_parser" ]
-    public_deps =  # no-presubmit-check TODO(webrtc:8603)
+    public_deps +=  # no-presubmit-check TODO(webrtc:8603)
         [ "../../logging:rtc_event_log_proto" ]
   }
 }

modules/audio_device/BUILD.gn

@@ -31,7 +31,7 @@ rtc_source_set("audio_device_default") {
 
 rtc_source_set("audio_device") {
   visibility = [ "*" ]
-  public_deps = [
+  public_deps += [  # no-presubmit-check TODO(webrtc:8603)
     ":audio_device_api",
 
     # Deprecated.

test/BUILD.gn

@@ -484,7 +484,6 @@ rtc_source_set("test_support") {
     "gtest.h",
   ]
 
-  public_deps = []  # no-presubmit-check TODO(webrtc:8603)
   if (is_ios) {
     public_deps +=  # no-presubmit-check TODO(webrtc:8603)
         [ ":test_support_objc" ]
@@ -915,9 +914,9 @@ rtc_library("fileutils_override_impl") {
 rtc_source_set("run_test") {
   testonly = true
   if (is_mac) {
-    public_deps = [ ":run_test_objc" ]  # no-presubmit-check TODO(webrtc:8603)
+    public_deps += [ ":run_test_objc" ]  # no-presubmit-check TODO(webrtc:8603)
   } else {
-    public_deps =  # no-presubmit-check TODO(webrtc:8603)
+    public_deps +=  # no-presubmit-check TODO(webrtc:8603)
         [ ":run_test_generic" ]
   }
 }
@@ -981,7 +980,7 @@ rtc_library("direct_transport") {
     "../rtc_base/task_utils:repeating_task",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/memory" ]
-  public_deps =  # no-presubmit-check TODO(webrtc:8603)
+  public_deps +=  # no-presubmit-check TODO(webrtc:8603)
       [ "../call:fake_network" ]
 }
 
@@ -1093,7 +1092,7 @@ rtc_library("mock_transport") {
 }
 
 rtc_source_set("test_renderer") {
-  public_deps =  # no-presubmit-check TODO(webrtc:8603)
+  public_deps +=  # no-presubmit-check TODO(webrtc:8603)
       [ ":test_renderer_generic" ]
   testonly = true
   if (is_mac) {

webrtc.gni

@@ -251,6 +251,15 @@ declare_args() {
   # with this string.
   # See the definition of RTC_OBJC_TYPE_PREFIX in the code.
   rtc_objc_prefix = ""
+
+  # Embedders can define dependencies needed by WebRTC. Dependencies can be
+  # configs or targets. This can be defined in their `.gn` file.
+  #
+  # In practise, this is use by Chromium: Targets from
+  # `//third_party/webrtc_overrides` are depending on Chrome's `//base`, but
+  # WebRTC does not declare its public dependencies. See webrtc:8603. Instead
+  # WebRTC is using a global common dependencies.
+  rtc_common_public_deps = []  # no-presubmit-check TODO(webrtc:8603)
 }
 
 if (!build_with_mozilla) {
@@ -387,34 +396,40 @@ rtc_library_impl_config = [ webrtc_root + ":library_impl_config" ]
 
 set_defaults("rtc_test") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
 }
 
 set_defaults("rtc_library") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
   absl_deps = []
 }
 
 set_defaults("rtc_source_set") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
   absl_deps = []
 }
 
 set_defaults("rtc_static_library") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
   absl_deps = []
 }
 
 set_defaults("rtc_executable") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
 }
 
 set_defaults("rtc_shared_library") {
   configs = rtc_add_configs
+  public_deps = rtc_common_public_deps  # no-presubmit-check TODO(webrtc:8603)
   suppressed_configs = []
 }