Fix build failure with "enable_webrtc = false".

content/content_renderer.gypi

Index: content/content_renderer.gypi
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index 42a6f76c297d204fed9442ea0f14572310bb5ab4..98f02164289a8786007f6c6d86a55836409692b7 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -68,8 +68,6 @@
       'public/renderer/document_state.cc',
       'public/renderer/document_state.h',
       'public/renderer/media_stream_audio_renderer.h',
-      'public/renderer/media_stream_audio_sink.cc',
-      'public/renderer/media_stream_audio_sink.h',
       'public/renderer/media_stream_sink.h',
       'public/renderer/navigation_state.cc',
       'public/renderer/navigation_state.h',
@@ -315,19 +313,10 @@
       'renderer/media/cdm/ppapi_decryptor.h',
       'renderer/media/cdm/render_cdm_factory.cc',
       'renderer/media/cdm/render_cdm_factory.h',
-      'renderer/media/html_audio_element_capturer_source.cc',
-      'renderer/media/html_audio_element_capturer_source.h',
-      'renderer/media/external_media_stream_audio_source.cc',
-      'renderer/media/external_media_stream_audio_source.h',
-      'renderer/media/local_media_stream_audio_source.cc',
-      'renderer/media/local_media_stream_audio_source.h',
       'renderer/media/media_permission_dispatcher.cc',
       'renderer/media/media_permission_dispatcher.h',
-      'renderer/media/media_stream_audio_deliverer.h',
       'renderer/media/media_stream_audio_level_calculator.cc',
       'renderer/media/media_stream_audio_level_calculator.h',
-      'renderer/media/media_stream_audio_source.cc',
-      'renderer/media/media_stream_audio_source.h',
       'renderer/media/media_stream_audio_track.cc',
       'renderer/media/media_stream_audio_track.h',
       'renderer/media/media_stream_center.h',
@@ -634,6 +623,8 @@
       'renderer/render_widget_fullscreen_pepper.h',
     ],
     'public_renderer_webrtc_sources': [
+      'public/renderer/media_stream_audio_sink.cc',
+      'public/renderer/media_stream_audio_sink.h',

[mcasas, 2016/08/29 16:56:38]

Hmm I'm wondering why to single out just these few 
files, and not bundle all media_stream_* files under
these categories -- context: WebRTC grew up to encompass
not just the RTCPeerConnection-supporting classes,
but also all MediaStream and derivatives work (like, e.g.
the html_*_element_capturer_source).

So why not move all said files in the ..._webtrc_sources 
categories?

Also, to better understand why this is done, could you
file a bug?

Don't bother running master.tryserver.webrtc bots, they
won't work (always fail to patch).

[Shouqun1, 2016/08/30 01:12:14]

@mcasas, I have filed a bug to tracking this issue: http://crbug.com/642210
and I'll firstly try to move MediaStream files into webrtc category.

       'public/renderer/media_stream_renderer_factory.h',
       'public/renderer/media_stream_utils.cc',
       'public/renderer/media_stream_utils.h',
@@ -650,6 +641,8 @@
       'renderer/media/audio_track_recorder.h',
       'renderer/media/canvas_capture_handler.cc',
       'renderer/media/canvas_capture_handler.h',
+      'renderer/media/external_media_stream_audio_source.cc',
+      'renderer/media/external_media_stream_audio_source.h',
       'renderer/media/gpu/rtc_video_decoder.cc',
       'renderer/media/gpu/rtc_video_decoder.h',
       'renderer/media/gpu/rtc_video_decoder_factory.cc',
@@ -658,18 +651,25 @@
       'renderer/media/gpu/rtc_video_encoder.h',
       'renderer/media/gpu/rtc_video_encoder_factory.cc',
       'renderer/media/gpu/rtc_video_encoder_factory.h',
+      'renderer/media/html_audio_element_capturer_source.cc',
+      'renderer/media/html_audio_element_capturer_source.h',
       'renderer/media/html_video_element_capturer_source.cc',
       'renderer/media/html_video_element_capturer_source.h',
       'renderer/media/image_capture_frame_grabber.cc',
       'renderer/media/image_capture_frame_grabber.h',
+      'renderer/media/local_media_stream_audio_source.cc',
+      'renderer/media/local_media_stream_audio_source.h',
       'renderer/media/media_recorder_handler.cc',
       'renderer/media/media_recorder_handler.h',
       'renderer/media/media_stream.cc',
       'renderer/media/media_stream.h',
+      'renderer/media/media_stream_audio_deliverer.h',
       'renderer/media/media_stream_audio_processor.cc',
       'renderer/media/media_stream_audio_processor.h',
       'renderer/media/media_stream_audio_processor_options.cc',
       'renderer/media/media_stream_audio_processor_options.h',
+      'renderer/media/media_stream_audio_source.cc',
+      'renderer/media/media_stream_audio_source.h',
       'renderer/media/media_stream_center.cc',
       'renderer/media/media_stream_dispatcher.cc',
       'renderer/media/media_stream_registry_interface.h',