Initialization of audio manager for Android is now done on the audio thread

media/audio/android/audio_manager_android.h

 // 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.
 
 #ifndef MEDIA_AUDIO_ANDROID_AUDIO_MANAGER_ANDROID_H_
 #define MEDIA_AUDIO_ANDROID_AUDIO_MANAGER_ANDROID_H_
 
 #include <set>
 
 #include "base/android/jni_android.h"
 #include "base/gtest_prod_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "media/audio/audio_manager_base.h"
 
 namespace media {
 
 class OpenSLESOutputStream;
 
 // Android implemention of AudioManager.
-class MEDIA_EXPORT AudioManagerAndroid : public AudioManagerBase {
+class MEDIA_EXPORT AudioManagerAndroid
+    : public AudioManagerBase,
+      public base::MessageLoop::DestructionObserver {
  public:
   AudioManagerAndroid(AudioLogFactory* audio_log_factory);
 
   // Implementation of AudioManager.
   virtual bool HasAudioOutputDevices() OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
   virtual void GetAudioInputDeviceNames(
       AudioDeviceNames* device_names) OVERRIDE;
   virtual void GetAudioOutputDeviceNames(
       AudioDeviceNames* device_names) OVERRIDE;
@@ skipping 27 matching lines @@
   void SetMute(JNIEnv* env, jobject obj, jboolean muted);
 
  protected:
   virtual ~AudioManagerAndroid();
 
   virtual AudioParameters GetPreferredOutputStreamParameters(
       const std::string& output_device_id,
       const AudioParameters& input_params) OVERRIDE;
 
  private:
-  bool HadNoAudioStreams();
+  // Implementation of MessageLoop::DestructionObserver.
+  virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
+
+  void CreateAndInitOnAudioThread();
+  void CloseOnAudioThread();
+
+  bool HasNoAudioStreams();
   void Init();
   void Close();
   void SetCommunicationAudioModeOn(bool on);
   bool SetAudioDevice(const std::string& device_id);
   int GetNativeOutputSampleRate();
   bool IsAudioLowLatencySupported();
   int GetAudioLowLatencyOutputFrameSize();
   int GetOptimalOutputFrameSize(int sample_rate, int channels);
 
   void DoSetMuteOnAudioThread(bool muted);
 
-  // Allow the AudioAndroidTest to access private methods.
-  FRIEND_TEST_ALL_PREFIXES(AudioAndroidOutputTest, IsAudioLowLatencySupported);
-
   // Java AudioManager instance.
   base::android::ScopedJavaGlobalRef<jobject> j_audio_manager_;
 
   typedef std::set<OpenSLESOutputStream*> OutputStreams;
   OutputStreams streams_;
-  // TODO(wjia): remove this lock once unit test modules are fixed to call
-  // AudioManager::MakeAudioOutputStream on the audio thread. For now, this
-  // lock is used to guard access to |streams_|.
-  base::Lock streams_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerAndroid);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_ANDROID_AUDIO_MANAGER_ANDROID_H_