Add a mojo implementation of AudioOutputIPC.

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
@@ skipping 656 matching lines @@
   peer_connection_factory_.reset(
       new PeerConnectionDependencyFactory(p2p_socket_dispatcher_.get()));
 
   aec_dump_message_filter_ = new AecDumpMessageFilter(
       GetIOTaskRunner(), message_loop()->task_runner());
 
   AddFilter(aec_dump_message_filter_.get());
 
 #endif  // BUILDFLAG(ENABLE_WEBRTC)
 
+  if (base::FeatureList::IsEnabled(
+          features::kUseMojoAudioOutputStreamFactory)) {
+    audio_ipc_factory_.emplace(GetIOTaskRunner());

[o1ka, 2017/04/20 10:36:00]

I'd prefer all the notion of kUseMojoAudioOutputStreamFactory to be hidden in
IPC factory.
audio_ipc_factory_ = AudioIPCFactory::Create(GetIOTaskRunner()); // no need for
optional
if (!audio_ipc_factory_) {
// create & reg a filter
}

[Max Morin, 2017/05/05 13:10:59]

I didn't do exactly this, PTAL.

+  } else {
+    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());
-
   midi_message_filter_ = new MidiMessageFilter(GetIOTaskRunner());
   AddFilter(midi_message_filter_.get());
 
   AddFilter((new CacheStorageMessageFilter(thread_safe_sender()))->GetFilter());
 
   AddFilter((new ServiceWorkerContextMessageFilter())->GetFilter());
 
 #if defined(USE_AURA)
   if (IsRunningInMash()) {
     CreateRenderWidgetWindowTreeClientFactory(GetServiceManagerConnection());
@@ skipping 1755 matching lines @@
   }
 }
 
 void RenderThreadImpl::OnRendererInterfaceRequest(
     mojom::RendererAssociatedRequest request) {
   DCHECK(!renderer_binding_.is_bound());
   renderer_binding_.Bind(std::move(request));
 }
 
 }  // namespace content