Change audio render thread checking to use new AudioRendererSink::BelongsToRendererThread()

media/audio/audio_output_device.cc

Index: media/audio/audio_output_device.cc
diff --git a/media/audio/audio_output_device.cc b/media/audio/audio_output_device.cc
index a3effebfb43af118500197a6eed9a48093563f7d..b8b0da6477146f65b46fa25ad37dc151c6b1e75a 100644
--- a/media/audio/audio_output_device.cc
+++ b/media/audio/audio_output_device.cc
@@ -39,6 +39,10 @@ class AudioOutputDevice::AudioThreadCallback
   // Called whenever we receive notifications about pending data.
   void Process(uint32_t pending_data) override;
 
+  // Returns whether the current thread is the audio device thread or not.
+  // Will always return true if DCHECKs are not enabled.
+  bool CurrentThreadIsAudioDeviceThread();
+
  private:
   AudioRendererSink::RenderCallback* render_callback_;
   std::unique_ptr<AudioBus> output_bus_;
@@ -150,6 +154,13 @@ OutputDeviceInfo AudioOutputDevice::GetOutputDeviceInfo() {
                           device_status_, output_params_);
 }
 
+bool AudioOutputDevice::CurrentThreadIsRenderingThread() {
+  // Since this function is supposed to be called on the rendering thread,

[DaleCurtis, 2016/06/14 17:07:49]

Hmm, seems like this should have a DCHECK(CurrentThreadIsAUdioDeviceThread()) :)
Note: calling this will actually bind the thread checker to the calling
thread... so failures will be confusing if the caller binds to a non-render
thread and then the render thread dcheck fails on the first render() call.

[Henrik Grunell, 2016/06/14 19:33:41]

Yes, a failure could be confusing if that happens. You mean a DCHECK would avoid
that? How? Or why have a DCHECK?

[DaleCurtis, 2016/06/14 20:07:16]

I'd just add some text to the DCHECK() on the audio thread that says this will
only fail if the thread checker was attached on the wrong thread.

[Henrik Grunell, 2016/06/15 07:17:54]

Done.

+  // it's safe to access |audio_callback_| here. It will always be valid when
+  // the rendering thread is running.
+  return audio_callback_->CurrentThreadIsAudioDeviceThread();
+}
+
 void AudioOutputDevice::RequestDeviceAuthorizationOnIOThread() {
   DCHECK(task_runner()->BelongsToCurrentThread());
   DCHECK_EQ(state_, IDLE);
@@ -450,4 +461,9 @@ void AudioOutputDevice::AudioThreadCallback::Process(uint32_t pending_data) {
                            frames_skipped);
 }
 
+bool AudioOutputDevice::AudioThreadCallback::
+    CurrentThreadIsAudioDeviceThread() {
+  return thread_checker_.CalledOnValidThread();
+}
+
 }  // namespace media