Switch to STA mode for audio thread and WASAPI I/O streams.

media/audio/win/audio_low_latency_output_win.h

Index: media/audio/win/audio_low_latency_output_win.h
diff --git a/media/audio/win/audio_low_latency_output_win.h b/media/audio/win/audio_low_latency_output_win.h
index 1584a4603df01eb13de4a3363a12753352327762..436e18d76714002abe0fdd470975a98fda7db964 100644
--- a/media/audio/win/audio_low_latency_output_win.h
+++ b/media/audio/win/audio_low_latency_output_win.h
@@ -157,7 +157,10 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // Checks available amount of space in the endpoint buffer and reads
   // data from the client to fill up the buffer without causing audio
   // glitches.
-  bool RenderAudioFromSource(UINT64 device_frequency);
+  bool RenderAudioFromSource(UINT64 device_frequency,
+                             IAudioClient* thread_audio_client,
+                             IAudioRenderClient* thread_audio_render_client,
+                             IAudioClock* thread_audio_clock);
 
   // Called when the device will be opened in exclusive mode and use the
   // application specified format.
@@ -172,6 +175,15 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // |source_| is set to NULL.
   void StopThread();
 
+  // Handles sharing of COM pointers between the audio and render threads.  The
+  // marshal method must be called on the audio manager thread, while unmarshal
+  // must be called on |render_thread_|.
+  bool MarshalComPointers();
+  void UnmarshalComPointers(
+      base::win::ScopedComPtr<IAudioClient>* audio_client,
+      base::win::ScopedComPtr<IAudioRenderClient>* audio_render_client,
+      base::win::ScopedComPtr<IAudioClock>* audio_clock);
+
   // Contains the thread ID of the creating thread.
   base::PlatformThreadId creating_thread_id_;
 
@@ -221,6 +233,18 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // Pointer to the client that will deliver audio samples to be played out.
   AudioSourceCallback* source_;
 
+  // ------------------------------------------------------
+  // Warning: COM pointers must be marshaled from the audio thread to be used
+  // on any other thread. Do not use any of these interfaces on a thread other
+  // than the audio thread.  See MarshalComPointers() and UnmarshalComPointers()
+  // for marshaling pointers to the render thread.
+
+  // Stream into which the COM pointers below are marshaled so that they can
+  // be used on another thread.
+  base::win::ScopedComPtr<IStream> com_stream_;
+
+  // Windows Audio Session API (WASAPI) interfaces.
+
   // An IAudioClient interface which enables a client to create and initialize
   // an audio stream between an audio application and the audio engine.
   base::win::ScopedComPtr<IAudioClient> audio_client_;
@@ -229,6 +253,9 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // data to a rendering endpoint buffer.
   base::win::ScopedComPtr<IAudioRenderClient> audio_render_client_;
 
+  base::win::ScopedComPtr<IAudioClock> audio_clock_;
+  // ------------------------------------------------------
+
   // The audio engine will signal this event each time a buffer becomes
   // ready to be filled by the client.
   base::win::ScopedHandle audio_samples_render_event_;
@@ -239,8 +266,6 @@ class MEDIA_EXPORT WASAPIAudioOutputStream :
   // Container for retrieving data from AudioSourceCallback::OnMoreData().
   scoped_ptr<AudioBus> audio_bus_;
 
-  base::win::ScopedComPtr<IAudioClock> audio_clock_;
-
   DISALLOW_COPY_AND_ASSIGN(WASAPIAudioOutputStream);
 };