Adds COM init to AudioManager thread for Windows

media/audio/audio_manager_base.cc

Index: media/audio/audio_manager_base.cc
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index 435cf9ee8c677ac4aa09f9f4490d40e366e75904..13eb32fa33537059ba6736316e4f903a0ec54031 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -39,6 +39,40 @@ static const int kMaxInputChannels = 2;
 const char AudioManagerBase::kDefaultDeviceName[] = "Default";
 const char AudioManagerBase::kDefaultDeviceId[] = "default";
 
+// Initializes the COM library for use by this thread and sets the thread's
+// COM threading model on Windows to MTA.
+class AudioThread : public base::Thread {
+public:
+  AudioThread();
+  virtual ~AudioThread();
+
+protected:
+  virtual void Init() OVERRIDE;
+  virtual void CleanUp() OVERRIDE;
+
+private:
+  scoped_ptr<base::win::ScopedCOMInitializer> com_initializer_;
+  DISALLOW_COPY_AND_ASSIGN(AudioThread);
+};
+
+AudioThread::AudioThread()
+    : base::Thread("AudioThread") {
+}
+
+AudioThread::~AudioThread() {
+  Stop();
+}
+
+void AudioThread::Init() {
+  using base::win::ScopedCOMInitializer;
+  com_initializer_.reset(new ScopedCOMInitializer(ScopedCOMInitializer::kMTA));
+  CHECK(com_initializer_->succeeded());
+}
+
+void AudioThread::CleanUp() {
+  com_initializer_.reset();
+}
+
 AudioManagerBase::AudioManagerBase()
     : num_active_input_streams_(0),
       max_num_output_streams_(kDefaultMaxOutputStreams),
@@ -63,7 +97,7 @@ AudioManagerBase::~AudioManagerBase() {
 void AudioManagerBase::Init() {
   base::AutoLock lock(audio_thread_lock_);
   DCHECK(!audio_thread_.get());
-  audio_thread_.reset(new base::Thread("AudioThread"));
+  audio_thread_.reset(new media::AudioThread());
   CHECK(audio_thread_->Start());
 }
 
@@ -228,7 +262,7 @@ bool AudioManagerBase::IsRecordingInProcess() {
 void AudioManagerBase::Shutdown() {
   // To avoid running into deadlocks while we stop the thread, shut it down
   // via a local variable while not holding the audio thread lock.
-  scoped_ptr<base::Thread> audio_thread;
+  scoped_ptr<media::AudioThread> audio_thread;
   {
     base::AutoLock lock(audio_thread_lock_);
     audio_thread_.swap(audio_thread);