Revert "Attempt to fix audio wedges by restarting all streams on OSX."

This reverts commit http://crrev.com/238501 in favor  a simpler approach
which delays stream creation around suspend and resume events:
http://crrev.com/247026

Care must be taken to monitor the UMA stat for increases after this lands.
I'll also communicate with the YT team on the bug/ to ensure they provide
some assistance in testing.

BUG=160920
TEST=No stream hangs.

Review URL: https://codereview.chromium.org/190553004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263076 0039d316-1c4b-4281-b951-d872f2087c98

media/audio/audio_manager.h

@@ -176,11 +176,6 @@ class MEDIA_EXPORT AudioManager {
   virtual scoped_ptr<AudioLog> CreateAudioLog(
       AudioLogFactory::AudioComponent component) = 0;
 
-  // Called when a component has detected a OS level audio wedge.  Shuts down
-  // all active audio streams and then restarts them transparently.  See
-  // http://crbug.com/160920
-  virtual void FixWedgedAudio() = 0;
-
  protected:
   AudioManager();
 

media/audio/audio_manager_base.cc

@@ -400,32 +400,4 @@ scoped_ptr<AudioLog> AudioManagerBase::CreateAudioLog(
   return audio_log_factory_->CreateAudioLog(component);
 }
 
-void AudioManagerBase::FixWedgedAudio() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-#if defined(OS_MACOSX)
-  // Through trial and error, we've found that one way to restore audio after a
-  // hang is to close all outstanding audio streams.  Once all streams have been
-  // closed, new streams appear to work correctly.
-  //
-  // In Chrome terms, this means we need to ask all AudioOutputDispatchers to
-  // close all Open()'d streams.  Once all streams across all dispatchers have
-  // been closed, we ask for all previously Start()'d streams to be recreated
-  // using the same AudioSourceCallback they had before.
-  //
-  // Since this operation takes place on the audio thread we can be sure that no
-  // other state-changing stream operations will take place while the fix is in
-  // progress.
-  //
-  // See http://crbug.com/160920 for additional details.
-  for (AudioOutputDispatchers::iterator it = output_dispatchers_.begin();
-       it != output_dispatchers_.end(); ++it) {
-    (*it)->dispatcher->CloseStreamsForWedgeFix();
-  }
-  for (AudioOutputDispatchers::iterator it = output_dispatchers_.begin();
-       it != output_dispatchers_.end(); ++it) {
-    (*it)->dispatcher->RestartStreamsForWedgeFix();
-  }
-#endif
-}
-
 }  // namespace media

media/audio/audio_manager_base.h

@@ -115,8 +115,6 @@ class MEDIA_EXPORT AudioManagerBase : public AudioManager {
   virtual scoped_ptr<AudioLog> CreateAudioLog(
       AudioLogFactory::AudioComponent component) OVERRIDE;
 
-  virtual void FixWedgedAudio() OVERRIDE;
-
  protected:
   AudioManagerBase(AudioLogFactory* audio_log_factory);
 

media/audio/audio_output_controller.cc

@@ -435,15 +435,8 @@ void AudioOutputController::WedgeCheck() {
 
   // If we should be playing and we haven't, that's a wedge.
   if (state_ == kPlaying) {
-    const bool playback_success =
-        base::AtomicRefCountIsOne(&on_more_io_data_called_);
-
-    UMA_HISTOGRAM_BOOLEAN(
-        "Media.AudioOutputControllerPlaybackStartupSuccess", playback_success);
-
-    // Let the AudioManager try and fix it.
-    if (!playback_success)
-      audio_manager_->FixWedgedAudio();
+    UMA_HISTOGRAM_BOOLEAN("Media.AudioOutputControllerPlaybackStartupSuccess",
+                          base::AtomicRefCountIsOne(&on_more_io_data_called_));
   }
 }
 

media/audio/audio_output_dispatcher.h

@@ -65,13 +65,6 @@ class MEDIA_EXPORT AudioOutputDispatcher
   // Called on the audio thread when the AudioManager is shutting down.
   virtual void Shutdown() = 0;
 
-  // Called by the AudioManager to restart streams when a wedge is detected.  A
-  // wedge means the OS failed to request any audio after StartStream().  When a
-  // wedge is detected all streams across all dispatchers must be closed.  After
-  // all streams are closed, streams are restarted.  See http://crbug.com/160920
-  virtual void CloseStreamsForWedgeFix() = 0;
-  virtual void RestartStreamsForWedgeFix() = 0;
-
   const std::string& device_id() const { return device_id_; }
 
  protected:

media/audio/audio_output_dispatcher_impl.cc

@@ -172,17 +172,4 @@ void AudioOutputDispatcherImpl::CloseIdleStreams(size_t keep_alive) {
   idle_streams_.erase(idle_streams_.begin() + keep_alive, idle_streams_.end());
 }
 
-void AudioOutputDispatcherImpl::CloseStreamsForWedgeFix() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  CloseAllIdleStreams();
-}
-
-void AudioOutputDispatcherImpl::RestartStreamsForWedgeFix() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  // Should only be called when the dispatcher is used with fake streams which
-  // don't need to be shutdown or restarted.
-  CHECK_EQ(params_.format(), AudioParameters::AUDIO_FAKE);
-}
-
 }  // namespace media

media/audio/audio_output_dispatcher_impl.h

@@ -61,9 +61,6 @@ class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
 
   virtual void Shutdown() OVERRIDE;
 
-  virtual void CloseStreamsForWedgeFix() OVERRIDE;
-  virtual void RestartStreamsForWedgeFix() OVERRIDE;
-
  private:
   friend class base::RefCountedThreadSafe<AudioOutputDispatcherImpl>;
   virtual ~AudioOutputDispatcherImpl();

media/audio/audio_output_proxy_unittest.cc

@@ -673,75 +673,4 @@ TEST_F(AudioOutputResamplerTest, LowLatencyOpenEventuallyFails) {
   EXPECT_TRUE(stream2.start_called());
 }
 
-// Ensures the methods used to fix audio output wedges are working correctly.
-TEST_F(AudioOutputResamplerTest, WedgeFix) {
-  MockAudioOutputStream stream1(&manager_, params_);
-  MockAudioOutputStream stream2(&manager_, params_);
-  MockAudioOutputStream stream3(&manager_, params_);
-
-  // Setup the mock such that all three streams are successfully created.
-  EXPECT_CALL(manager(), MakeAudioOutputStream(_, _))
-      .WillOnce(Return(&stream1))
-      .WillOnce(Return(&stream2))
-      .WillOnce(Return(&stream3));
-
-  // Stream1 should be able to successfully open and start.
-  EXPECT_CALL(stream1, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream1, SetVolume(_));
-  EXPECT_CALL(stream2, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream2, SetVolume(_));
-
-  // Open and start the first proxy and stream.
-  AudioOutputProxy* proxy1 = new AudioOutputProxy(resampler_.get());
-  EXPECT_TRUE(proxy1->Open());
-  proxy1->Start(&callback_);
-  OnStart();
-
-  // Open, but do not start the second proxy.
-  AudioOutputProxy* proxy2 = new AudioOutputProxy(resampler_.get());
-  EXPECT_TRUE(proxy2->Open());
-
-  // Open, start and then stop the third proxy.
-  AudioOutputProxy* proxy3 = new AudioOutputProxy(resampler_.get());
-  EXPECT_TRUE(proxy3->Open());
-  proxy3->Start(&callback_);
-  OnStart();
-  proxy3->Stop();
-
-  // Wait for stream to timeout and shutdown.
-  WaitForCloseTimer(&stream2);
-
-  EXPECT_CALL(stream1, Close());
-  resampler_->CloseStreamsForWedgeFix();
-
-  // Don't pump the MessageLoop between CloseStreamsForWedgeFix() and
-  // RestartStreamsForWedgeFix() to simulate intended usage.  The OnStart() call
-  // will take care of necessary work.
-
-  // Stream3 should take Stream1's place after RestartStreamsForWedgeFix().  No
-  // additional streams should be opened for proxy2 and proxy3.
-  EXPECT_CALL(stream3, Open())
-      .WillOnce(Return(true));
-  EXPECT_CALL(stream3, SetVolume(_));
-
-  resampler_->RestartStreamsForWedgeFix();
-  OnStart();
-
-  // Perform the required Stop()/Close() shutdown dance for each proxy.
-  proxy3->Close();
-  proxy2->Close();
-  proxy1->Stop();
-  CloseAndWaitForCloseTimer(proxy1, &stream3);
-
-  // Wait for all of the messages to fly and then verify stream behavior.
-  EXPECT_TRUE(stream1.stop_called());
-  EXPECT_TRUE(stream1.start_called());
-  EXPECT_TRUE(stream2.stop_called());
-  EXPECT_TRUE(stream2.start_called());
-  EXPECT_TRUE(stream3.stop_called());
-  EXPECT_TRUE(stream3.start_called());
-}
-
 }  // namespace media

media/audio/audio_output_resampler.cc

@@ -298,37 +298,6 @@ void AudioOutputResampler::Shutdown() {
   DCHECK(callbacks_.empty());
 }
 
-void AudioOutputResampler::CloseStreamsForWedgeFix() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  // Stop and close all active streams.  Once all streams across all dispatchers
-  // have been closed the AudioManager will call RestartStreamsForWedgeFix().
-  for (CallbackMap::iterator it = callbacks_.begin(); it != callbacks_.end();
-       ++it) {
-    if (it->second->started())
-      dispatcher_->StopStream(it->first);
-    dispatcher_->CloseStream(it->first);
-  }
-
-  // Close all idle streams as well.
-  dispatcher_->CloseStreamsForWedgeFix();
-}
-
-void AudioOutputResampler::RestartStreamsForWedgeFix() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  // By opening all streams first and then starting them one by one we ensure
-  // the dispatcher only opens streams for those which will actually be used.
-  for (CallbackMap::iterator it = callbacks_.begin(); it != callbacks_.end();
-       ++it) {
-    dispatcher_->OpenStream();
-  }
-  for (CallbackMap::iterator it = callbacks_.begin(); it != callbacks_.end();
-       ++it) {
-    if (it->second->started())
-      dispatcher_->StartStream(it->second, it->first);
-  }
-}
-
 OnMoreDataConverter::OnMoreDataConverter(const AudioParameters& input_params,
                                          const AudioParameters& output_params)
     : io_ratio_(static_cast<double>(input_params.GetBytesPerSecond()) /

media/audio/audio_output_resampler.h

@@ -52,8 +52,6 @@ class MEDIA_EXPORT AudioOutputResampler : public AudioOutputDispatcher {
                                double volume) OVERRIDE;
   virtual void CloseStream(AudioOutputProxy* stream_proxy) OVERRIDE;
   virtual void Shutdown() OVERRIDE;
-  virtual void CloseStreamsForWedgeFix() OVERRIDE;
-  virtual void RestartStreamsForWedgeFix() OVERRIDE;
 
  private:
   friend class base::RefCountedThreadSafe<AudioOutputResampler>;

media/audio/mock_audio_manager.cc

@@ -107,6 +107,4 @@ scoped_ptr<AudioLog> MockAudioManager::CreateAudioLog(
   return scoped_ptr<AudioLog>();
 }
 
-void MockAudioManager::FixWedgedAudio() {}
-
 }  // namespace media.

media/audio/mock_audio_manager.h

@@ -70,8 +70,6 @@ class MockAudioManager : public media::AudioManager {
   virtual scoped_ptr<AudioLog> CreateAudioLog(
       AudioLogFactory::AudioComponent component) OVERRIDE;
 
-  virtual void FixWedgedAudio() OVERRIDE;
-
  protected:
   virtual ~MockAudioManager();