Fix start/stop of html5 audio stream and race condition when pausing.

content/renderer/media/webrtc_audio_device_impl.cc

 // Copyright (c) 2011 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 "content/renderer/media/webrtc_audio_device_impl.h"
 
 #include "base/bind.h"
 #include "base/string_util.h"
 #include "base/win/windows_version.h"
 #include "content/renderer/media/audio_hardware.h"
@@ skipping 41 matching lines @@
 }
 
 int32_t WebRtcAudioDeviceImpl::Release() {
   int ret = base::subtle::Barrier_AtomicIncrement(&ref_count_, -1);
   if (ret == 0) {
     delete this;
   }
   return ret;
 }
 
-void WebRtcAudioDeviceImpl::Render(
+size_t WebRtcAudioDeviceImpl::Render(
     const std::vector<float*>& audio_data,
     size_t number_of_frames,
     size_t audio_delay_milliseconds) {
   DCHECK_LE(number_of_frames, output_buffer_size_);
 
   // Store the reported audio delay locally.
   output_delay_ms_ = audio_delay_milliseconds;
 
   const int channels = audio_data.size();
   DCHECK_LE(channels, output_channels_);
@@ skipping 31 matching lines @@
   // with nominal range -1.0 -> +1.0 to match the callback format.
   for (int channel_index = 0; channel_index < channels; ++channel_index) {
     media::DeinterleaveAudioChannel(
         output_buffer_.get(),
         audio_data[channel_index],
         channels,
         channel_index,
         bytes_per_sample_,
         number_of_frames);
   }
+  return number_of_frames;
 }
 
 void WebRtcAudioDeviceImpl::Capture(
     const std::vector<float*>& audio_data,
     size_t number_of_frames,
     size_t audio_delay_milliseconds) {
   DCHECK_LE(number_of_frames, input_buffer_size_);
 
   // Store the reported audio delay locally.
   input_delay_ms_ = audio_delay_milliseconds;
@@ skipping 842 matching lines @@
 }
 
 int32_t WebRtcAudioDeviceImpl::GetLoudspeakerStatus(bool* enabled) const {
   NOTIMPLEMENTED();
   return -1;
 }
 
 void WebRtcAudioDeviceImpl::SetSessionId(int session_id) {
   session_id_ = session_id;
 }