Revert 276939 "Decouple IPC::MessageFilter from IPC::Channel"

content/browser/renderer_host/media/audio_renderer_host.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/browser/renderer_host/media/audio_renderer_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/shared_memory.h"
 #include "base/metrics/histogram.h"
@@ skipping 137 matching lines @@
     const RenderViewHost::GetAudioOutputControllersCallback& callback) const {
   BrowserThread::PostTaskAndReplyWithResult(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&AudioRendererHost::DoGetOutputControllers, this,
                  render_view_id),
       callback);
 }
 
 void AudioRendererHost::OnChannelClosing() {
-  // Since the IPC sender is gone, close all requested audio streams.
+  // Since the IPC channel is gone, close all requested audio streams.
   while (!audio_entries_.empty()) {
     // Note: OnCloseStream() removes the entries from audio_entries_.
     OnCloseStream(audio_entries_.begin()->first);
   }
 }
 
 void AudioRendererHost::OnDestruct() const {
   BrowserThread::DeleteOnIOThread::Destruct(this);
 }
 
@@ skipping 329 matching lines @@
 
   AudioEntryMap::const_iterator i = audio_entries_.find(stream_id);
   return i != audio_entries_.end() ? i->second : NULL;
 }
 
 bool AudioRendererHost::HasActiveAudio() {
   return !base::AtomicRefCountIsZero(&num_playing_streams_);
 }
 
 }  // namespace content