There is a racing between SyncSocket::Receive in audio_thread_ and SyncSocket::Close in renderer ...

content/renderer/renderer_webaudiodevice_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/renderer_webaudiodevice_impl.h"
 
 using WebKit::WebAudioDevice;
 using WebKit::WebVector;
 
 RendererWebAudioDeviceImpl::RendererWebAudioDeviceImpl(size_t buffer_size,
     int channels, double sample_rate, WebAudioDevice::RenderCallback* callback)
     : is_running_(false),
       client_callback_(callback) {
   audio_device_ = new AudioDevice(buffer_size, channels, sample_rate, this);
 }
 
 RendererWebAudioDeviceImpl::~RendererWebAudioDeviceImpl() {
   stop();
 }
 
 void RendererWebAudioDeviceImpl::start() {
   if (!is_running_) {
     audio_device_->Start();
     is_running_ = true;
   }
 }
 
 void RendererWebAudioDeviceImpl::stop() {
   if (is_running_) {
-    if (audio_device_->Stop())
-      is_running_ = false;
+    audio_device_->Stop();
+    is_running_ = false;
   }
 }
 
 double RendererWebAudioDeviceImpl::sampleRate() {
   return 44100.0;
 }
 
 void RendererWebAudioDeviceImpl::Render(const std::vector<float*>& audio_data,
                                 size_t number_of_frames,
                                 size_t audio_delay_milliseconds) {
   // Make the client callback to get rendered audio.
   DCHECK(client_callback_);
   if (client_callback_) {
     // Wrap the pointers using WebVector.
     WebVector<float*> web_audio_data(audio_data.size());
     for (size_t i = 0; i < audio_data.size(); ++i)
       web_audio_data[i] = audio_data[i];
 
     client_callback_->render(web_audio_data, number_of_frames);
   }
 }