Remove some rtc hacks in the GN build.

Remove explicitly depending on a webrtc config now that it is correctly
exported from webrtc.

R=kjellander@chromium.org

Review URL: https://codereview.chromium.org/534813002

Cr-Commit-Position: refs/heads/master@{#294424}

chrome/browser/extensions/BUILD.gn

@@ -80,11 +80,6 @@ static_library("extensions") {
     "//content/public/browser",
   ]
 
-  # TODO(GYP) This config should be a direct_dependent_config of 
-  # //third_party/webrtc/modules/desktop_capture so we shouldn't have to
-  # include it here. Remove this line when the direct_dependent_config is set.
-  configs += [ "//third_party/webrtc:common_inherited_config" ]
-
   if (is_chromeos) {
     sources += rebase_path(
         gypi_values.chrome_browser_extensions_chromeos_sources,

remoting/base/BUILD.gn

@@ -91,10 +91,5 @@ static_library("base") {
     "//remoting/proto",
     "//third_party/protobuf:protobuf_lite",
   ]
-
-  # TODO(GYP) This config should be a direct_dependent_config of 
-  # //third_party/webrtc/modules/desktop_capture so we shouldn't have to
-  # include it here. Remove this line when the direct_dependent_config is set.
-  configs += [ "//third_party/webrtc:common_inherited_config" ]
 }
 

third_party/libjingle/BUILD.gn

@@ -516,10 +516,6 @@ if (enable_webrtc) {
       "//third_party/webrtc/modules/video_render",
     ]
 
-    # TODO(GYP) this should be removed and we should get this config by one of
-    # the webrtc targets specifying it for the direct_dependent_configs.
-    #configs += [ "//third_party/webrtc:common_config" ]  # TODO(GYP)
-
     if (!is_ios) {
       # TODO(mallinath) - Enable SCTP for iOS.
       sources += [