Add generic interfaces for the sinks of the media stream audio track

content/content_renderer.gypi

Index: content/content_renderer.gypi
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index 5791a21599f87961436f27cae5bb649132ed8c89..d8b80eb15a7210c5b1c818157fe41c3709369dbe 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -580,11 +580,15 @@
         '<(DEPTH)/crypto/crypto.gyp:crypto',
       ],
       'sources': [
+        'public/renderer/media_stream_audio_sink.h',
+        'public/renderer/media_stream_audio_sink.cc',
         'public/renderer/webrtc_log_message_delegate.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_sink_owner.cc',
+        'renderer/media/media_stream_audio_sink_owner.h',
         'renderer/media/media_stream_center.cc',
         'renderer/media/media_stream_dependency_factory.cc',
         'renderer/media/media_stream_dispatcher.cc',
@@ -632,8 +636,6 @@
         'renderer/media/webaudio_capturer_source.h',
         'renderer/media/webrtc_audio_capturer.cc',
         'renderer/media/webrtc_audio_capturer.h',
-        'renderer/media/webrtc_audio_capturer_sink_owner.cc',
-        'renderer/media/webrtc_audio_capturer_sink_owner.h',
         'renderer/media/webrtc_audio_device_impl.cc',
         'renderer/media/webrtc_audio_device_impl.h',
         'renderer/media/webrtc_audio_device_not_impl.cc',