Code: void AudioOutputDevice::OnStateChanged(AudioOutputIPCDelegate::State state) {
  DCHECK(message_loop()->BelongsToCurrentThread());

  if (!stream_id_)
    return;

  if (state == AudioOutputIPCDelegate::kError) {
    DLOG(WARNING) << "AudioOutputDevice::OnStateChanged(kError)";
    base::AutoLock auto_lock_(audio_thread_lock_);
    if (audio_thread_.get() && !audio_thread_->IsStopped())
       callback_->OnRenderError();
   }
 }

Vulnerability Type: Exec Code 
CWE ID: CWE-362
Summary: Race condition in Google Chrome before 22.0.1229.92 allows remote attackers to execute arbitrary code via vectors related to audio devices.
Commit Message: Revert r157378 as it caused WebRTC to dereference null pointers when restarting a call.

I've kept my unit test changes intact but disabled until I get a proper fix.

BUG=147499,150805
TBR=henrika

Review URL: https://codereview.chromium.org/10946040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@157626 0039d316-1c4b-4281-b951-d872f2087c98