media: Introduce Renderer interface and RendererImpl.

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 572 matching lines @@
       audio_clock_->WroteAudio(
           frames_written, delay_frames, playback_rate_, algorithm_->GetTime());
     }
     audio_clock_->WroteSilence(requested_frames - frames_written, delay_frames);
 
     if (frames_written == 0) {
       if (received_end_of_stream_ && !rendered_end_of_stream_ &&
           audio_clock_->CurrentMediaTimestamp(base::TimeDelta()) ==
               audio_clock_->last_endpoint_timestamp()) {
         rendered_end_of_stream_ = true;
-        ended_cb_.Run();
+        task_runner_->PostTask(FROM_HERE, ended_cb_);

[xhwang, 2014/07/25 00:39:29]

Post ended_cb_ so that we don't need to force posting in RendererImpl, as we did
in Pipeline.

       } else if (!received_end_of_stream_ && state_ == kPlaying) {
         if (buffering_state_ != BUFFERING_HAVE_NOTHING) {
           algorithm_->IncreaseQueueCapacity();
           SetBufferingState_Locked(BUFFERING_HAVE_NOTHING);
         }
       }
     }
 
     if (CanRead_Locked()) {
       task_runner_->PostTask(FROM_HERE,
@@ skipping 85 matching lines @@
            << buffering_state;
   DCHECK_NE(buffering_state_, buffering_state);
   lock_.AssertAcquired();
   buffering_state_ = buffering_state;
 
   task_runner_->PostTask(FROM_HERE,
                          base::Bind(buffering_state_cb_, buffering_state_));
 }
 
 }  // namespace media