Moved the fake input stream's processing onto the audio worker thread.

content/browser/media/capture/web_contents_audio_muter.cc

 // Copyright 2014 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/media/capture/web_contents_audio_muter.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "content/browser/media/capture/audio_mirroring_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager.h"
-#include "media/audio/fake_audio_consumer.h"
+#include "media/audio/fake_audio_worker.h"
 #include "media/base/bind_to_current_loop.h"
 
 namespace content {
 
 namespace {
 
 // An AudioOutputStream that pumps audio data, but does nothing with it.
 // Pumping the audio data is necessary because video playback is synchronized to
 // the audio stream and will freeze otherwise.
 //
 // TODO(miu): media::FakeAudioOutputStream does pretty much the same thing as
 // this class, but requires construction/destruction via media::AudioManagerBase
 // on the audio thread.  Once that's fixed, this class will no longer be needed.
 // http://crbug.com/416278
 class AudioDiscarder : public media::AudioOutputStream {
  public:
   explicit AudioDiscarder(const media::AudioParameters& params)
-      : consumer_(media::AudioManager::Get()->GetWorkerTaskRunner(), params) {}
+      : worker_(media::AudioManager::Get()->GetWorkerTaskRunner(), params),
+        audio_bus_(media::AudioBus::Create(params)) {}
 
   // AudioOutputStream implementation.
   bool Open() override { return true; }
   void Start(AudioSourceCallback* callback) override {
-    consumer_.Start(base::Bind(&AudioDiscarder::FetchAudioData, callback));
+    worker_.Start(base::Bind(&AudioDiscarder::FetchAudioData,
+                             base::Unretained(this),
+                             callback));
   }
-  void Stop() override { consumer_.Stop(); }
+  void Stop() override { worker_.Stop(); }
   void SetVolume(double volume) override {}
   void GetVolume(double* volume) override { *volume = 0; }
   void Close() override { delete this; }
 
  private:
   ~AudioDiscarder() override {}
 
-  static void FetchAudioData(AudioSourceCallback* callback,
-                             media::AudioBus* audio_bus) {
-    callback->OnMoreData(audio_bus, 0);
+  void FetchAudioData(AudioSourceCallback* callback) {
+    callback->OnMoreData(audio_bus_.get(), 0);
   }
 
   // Calls FetchAudioData() at regular intervals and discards the data.
-  media::FakeAudioConsumer consumer_;
+  media::FakeAudioWorker worker_;
+  scoped_ptr<media::AudioBus> audio_bus_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDiscarder);
 };
 
 }  // namespace
 
 // A simple AudioMirroringManager::MirroringDestination implementation that
 // identifies the audio streams rendered by a WebContents and provides
 // AudioDiscarders to AudioMirroringManager.
 class WebContentsAudioMuter::MuteDestination
@@ skipping 78 matching lines @@
   is_muting_ = false;
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&AudioMirroringManager::StopMirroring,
                  base::Unretained(AudioMirroringManager::GetInstance()),
                  destination_));
 }
 
 }  // namespace content