Decouple 'give me more data' and 'rendered end of stream' audio callbacks.

media/filters/audio_renderer_base.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_base.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 254 matching lines @@
     audio_time_cb_.Run(new_current_time, last_fill_buffer_time);
   }
 
   if (!underflow_cb.is_null())
     underflow_cb.Run();
 
   return dest_written;
 }
 
 void AudioRendererBase::SignalEndOfStream() {
-  DCHECK(recieved_end_of_stream_);
-  if (!rendered_end_of_stream_) {
+  // Lock, there is potential race condition on
+  // |recieved_end_of_stream_| and |rendered_end_of_stream_|.
+  base::AutoLock auto_lock(lock_);
+  if (recieved_end_of_stream_ && !rendered_end_of_stream_) {
     rendered_end_of_stream_ = true;
     host()->NotifyEnded();
   }
 }
 
 void AudioRendererBase::ScheduleRead_Locked() {
   lock_.AssertAcquired();
   if (pending_read_ || state_ == kPaused)
     return;
   pending_read_ = true;
   decoder_->Read(read_cb_);
 }
 
 void AudioRendererBase::SetPlaybackRate(float playback_rate) {
   base::AutoLock auto_lock(lock_);
   algorithm_->SetPlaybackRate(playback_rate);
 }
 
 float AudioRendererBase::GetPlaybackRate() {
   base::AutoLock auto_lock(lock_);
   return algorithm_->playback_rate();
 }
 
 bool AudioRendererBase::IsBeforeSeekTime(const scoped_refptr<Buffer>& buffer) {
   return (state_ == kSeeking) && buffer && !buffer->IsEndOfStream() &&
       (buffer->GetTimestamp() + buffer->GetDuration()) < seek_timestamp_;
 }
 
 }  // namespace media