Move OnDecoderInitDone() from decoder to pipeline thread.

media/filters/audio_renderer_impl.cc

Index: media/filters/audio_renderer_impl.cc
diff --git a/media/filters/audio_renderer_impl.cc b/media/filters/audio_renderer_impl.cc
index 2805ed05837293fa6ea1c6f245393f8f8a35bf8f..003881b88aa00b20d380490da6ed816c867c4870 100644
--- a/media/filters/audio_renderer_impl.cc
+++ b/media/filters/audio_renderer_impl.cc
@@ -13,7 +13,9 @@
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/message_loop_proxy.h"
 #include "media/audio/audio_util.h"
+#include "media/base/bind_to_loop.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/media_switches.h"
 
@@ -31,9 +33,12 @@ AudioRendererImpl::AudioRendererImpl(media::AudioRendererSink* sink)
       sink_(sink),
       underflow_disabled_(false),
       preroll_aborted_(false) {
+  // We're created on the render thread, but this thread checker is for another.
+  pipeline_thread_checker_.DetachFromThread();
 }
 
 void AudioRendererImpl::Play(const base::Closure& callback) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   {
     base::AutoLock auto_lock(lock_);
     DCHECK_EQ(kPaused, state_);
@@ -52,11 +57,13 @@ void AudioRendererImpl::Play(const base::Closure& callback) {
 }
 
 void AudioRendererImpl::DoPlay() {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   earliest_end_time_ = base::Time::Now();
   sink_->Play();
 }
 
 void AudioRendererImpl::Pause(const base::Closure& callback) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   {
     base::AutoLock auto_lock(lock_);
     DCHECK(state_ == kPlaying || state_ == kUnderflow ||
@@ -76,23 +83,26 @@ void AudioRendererImpl::Pause(const base::Closure& callback) {
 }
 
 void AudioRendererImpl::DoPause() {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   sink_->Pause(false);
 }
 
 void AudioRendererImpl::Flush(const base::Closure& callback) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   decoder_->Reset(callback);
 }
 
 void AudioRendererImpl::Stop(const base::Closure& callback) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   DCHECK(!callback.is_null());
 
+  if (!stopped_) {
+    sink_->Stop();
+    stopped_ = true;
+  }
+
   {
     base::AutoLock auto_lock(lock_);
-    if (!stopped_) {
-      sink_->Stop();
-      stopped_ = true;
-    }
-
     state_ = kStopped;
     algorithm_.reset(NULL);
     init_cb_.Reset();
@@ -105,28 +115,31 @@ void AudioRendererImpl::Stop(const base::Closure& callback) {
 
 void AudioRendererImpl::Preroll(base::TimeDelta time,
                                 const PipelineStatusCB& cb) {
-  base::AutoLock auto_lock(lock_);
-  DCHECK_EQ(kPaused, state_);
-  DCHECK(!pending_read_) << "Pending read must complete before seeking";
-  DCHECK(pause_cb_.is_null());
-  DCHECK(preroll_cb_.is_null());
-  state_ = kPrerolling;
-  preroll_cb_ = cb;
-  preroll_timestamp_ = time;
-
-  // Throw away everything and schedule our reads.
-  audio_time_buffered_ = kNoTimestamp();
-  current_time_ = kNoTimestamp();
-  received_end_of_stream_ = false;
-  rendered_end_of_stream_ = false;
-  preroll_aborted_ = false;
-
-  // |algorithm_| will request more reads.
-  algorithm_->FlushBuffers();
-
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   if (stopped_)
     return;
 
+  {
+    base::AutoLock auto_lock(lock_);
+    DCHECK_EQ(kPaused, state_);
+    DCHECK(!pending_read_) << "Pending read must complete before seeking";
+    DCHECK(pause_cb_.is_null());
+    DCHECK(preroll_cb_.is_null());
+    state_ = kPrerolling;
+    preroll_cb_ = cb;
+    preroll_timestamp_ = time;
+
+    // Throw away everything and schedule our reads.
+    audio_time_buffered_ = kNoTimestamp();
+    current_time_ = kNoTimestamp();
+    received_end_of_stream_ = false;
+    rendered_end_of_stream_ = false;
+    preroll_aborted_ = false;
+
+    // |algorithm_| will request more reads.
+    algorithm_->FlushBuffers();
+  }
+
   // Pause and flush the stream when we preroll to a new location.
   earliest_end_time_ = base::Time::Now();
   sink_->Pause(true);
@@ -141,7 +154,7 @@ void AudioRendererImpl::Initialize(const scoped_refptr<DemuxerStream>& stream,
                                    const base::Closure& ended_cb,
                                    const base::Closure& disabled_cb,
                                    const PipelineStatusCB& error_cb) {
-  base::AutoLock auto_lock(lock_);
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   DCHECK(stream);
   DCHECK(!decoders.empty());
   DCHECK_EQ(stream->type(), DemuxerStream::AUDIO);
@@ -169,7 +182,7 @@ void AudioRendererImpl::Initialize(const scoped_refptr<DemuxerStream>& stream,
 void AudioRendererImpl::InitializeNextDecoder(
     const scoped_refptr<DemuxerStream>& demuxer_stream,
     scoped_ptr<AudioDecoderList> decoders) {
-  lock_.AssertAcquired();
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   DCHECK(!decoders->empty());
 
   scoped_refptr<AudioDecoder> decoder = decoders->front();
@@ -177,13 +190,10 @@ void AudioRendererImpl::InitializeNextDecoder(
 
   DCHECK(decoder);
   decoder_ = decoder;
-
-  base::AutoUnlock auto_unlock(lock_);
   decoder->Initialize(
-      demuxer_stream,
-      base::Bind(&AudioRendererImpl::OnDecoderInitDone, this,
-                 demuxer_stream,
-                 base::Passed(&decoders)),
+      demuxer_stream, BindToLoop(base::MessageLoopProxy::current(), base::Bind(
+          &AudioRendererImpl::OnDecoderInitDone, this, demuxer_stream,
+          base::Passed(&decoders))),
       statistics_cb_);
 }
 
@@ -191,7 +201,7 @@ void AudioRendererImpl::OnDecoderInitDone(
     const scoped_refptr<DemuxerStream>& demuxer_stream,
     scoped_ptr<AudioDecoderList> decoders,
     PipelineStatus status) {
-  base::AutoLock auto_lock(lock_);
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
 
   if (state_ == kStopped) {
     DCHECK(stopped_);
@@ -267,14 +277,16 @@ void AudioRendererImpl::OnDecoderInitDone(
   audio_parameters_ = AudioParameters(
       format, channel_layout, sample_rate, bits_per_channel, buffer_size);
 
+  state_ = kPaused;
+
   sink_->Initialize(audio_parameters_, this);
   sink_->Start();
 
-  state_ = kPaused;
   base::ResetAndReturn(&init_cb_).Run(PIPELINE_OK);
 }
 
 void AudioRendererImpl::ResumeAfterUnderflow(bool buffer_more_audio) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   base::AutoLock auto_lock(lock_);
   if (state_ == kUnderflow) {
     // The "&& preroll_aborted_" is a hack. If preroll is aborted, then we
@@ -291,6 +303,7 @@ void AudioRendererImpl::ResumeAfterUnderflow(bool buffer_more_audio) {
 }
 
 void AudioRendererImpl::SetVolume(float volume) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   if (stopped_)
     return;
   sink_->SetVolume(volume);
@@ -376,6 +389,7 @@ void AudioRendererImpl::ScheduleRead_Locked() {
 }
 
 void AudioRendererImpl::SetPlaybackRate(float playback_rate) {
+  DCHECK(pipeline_thread_checker_.CalledOnValidThread());
   DCHECK_LE(0.0f, playback_rate);
 
   if (!stopped_) {