Add a mojo implementation of AudioOutputIPC.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index efeb21abff80f2a2b1ba8fddd2bb045f9bc7583c..9db376772b25484532d9038285fc03a5e6cb1c54 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -701,11 +701,13 @@ void RenderThreadImpl::Init(
 
 #endif  // BUILDFLAG(ENABLE_WEBRTC)
 
+  audio_message_filter_ = new AudioMessageFilter(GetIOTaskRunner());
+  AddFilter(audio_message_filter_.get());
+
   audio_input_message_filter_ = new AudioInputMessageFilter(GetIOTaskRunner());
   AddFilter(audio_input_message_filter_.get());
 
-  audio_message_filter_ = new AudioMessageFilter(GetIOTaskRunner());
-  AddFilter(audio_message_filter_.get());
+  audio_ipc_factory_.emplace(GetIOTaskRunner(), audio_message_filter_.get());

[o1ka, 2017/05/11 10:58:41]

Make it own |audio_message_filter_|? And remove audio_message_filter() getter
from renderer thread?

[Max Morin, 2017/05/11 15:31:18]

Done. Now AudioMessageFilter is completely cannibalized :).

 
   midi_message_filter_ = new MidiMessageFilter(GetIOTaskRunner());
   AddFilter(midi_message_filter_.get());