Always run AudioRendererImpl's flush callback asynchronously.

media/filters/audio_renderer_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/audio_renderer_impl.h"
 
 #include <math.h>
 
 #include <algorithm>
 
@@ skipping 167 matching lines @@
     // Flush() may have been called while underflowed/not fully buffered.
     if (buffering_state_ != BUFFERING_HAVE_NOTHING)
       SetBufferingState_Locked(BUFFERING_HAVE_NOTHING);
 
     earliest_end_time_ = now_cb_.Run();
     splicer_->Reset();
     if (buffer_converter_)
       buffer_converter_->Reset();
     algorithm_->FlushBuffers();
   }
-  base::ResetAndReturn(&flush_cb_).Run();
+
+  // Changes in buffering state are always posted. Flush callback must only be
+  // run after buffering state has been set back to nothing.
+  task_runner_->PostTask(FROM_HERE, base::ResetAndReturn(&flush_cb_));
 }
 
 void AudioRendererImpl::Stop(const base::Closure& callback) {
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!callback.is_null());
 
   // TODO(scherkus): Consider invalidating |weak_factory_| and replacing
   // task-running guards that check |state_| with DCHECK().
 
@@ skipping 51 matching lines @@
   DCHECK(!buffering_state_cb.is_null());
   DCHECK(!ended_cb.is_null());
   DCHECK(!error_cb.is_null());
   DCHECK_EQ(kUninitialized, state_);
   DCHECK(sink_);
 
   state_ = kInitializing;
 
   init_cb_ = init_cb;
   time_cb_ = time_cb;
-  // Callback can be run from audio callback thread in Render().
-  buffering_state_cb_ = BindToCurrentLoop(buffering_state_cb);
+  buffering_state_cb_ = buffering_state_cb;
   ended_cb_ = ended_cb;
   error_cb_ = error_cb;
 
   expecting_config_changes_ = stream->SupportsConfigChanges();
   if (!expecting_config_changes_) {
     // The actual buffer size is controlled via the size of the AudioBus
     // provided to Render(), so just choose something reasonable here for looks.
     int buffer_size = stream->audio_decoder_config().samples_per_second() / 100;
     audio_parameters_.Reset(
         AudioParameters::AUDIO_PCM_LOW_LATENCY,
@@ skipping 449 matching lines @@
     CHECK(splicer_->AddInput(buffer_converter_->GetNextBuffer()));
 }
 
 void AudioRendererImpl::SetBufferingState_Locked(
     BufferingState buffering_state) {
   DVLOG(1) << __FUNCTION__ << " : " << buffering_state_ << " -> "
            << buffering_state;
   DCHECK_NE(buffering_state_, buffering_state);
   lock_.AssertAcquired();
   buffering_state_ = buffering_state;
-  buffering_state_cb_.Run(buffering_state_);
+
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(buffering_state_cb_, buffering_state_));
 }
 
 }  // namespace media