Code: AudioOutputDevice::AudioOutputDevice(
    AudioOutputIPC* ipc,
    const scoped_refptr<base::MessageLoopProxy>& io_loop)
    : ScopedLoopObserver(io_loop),
      input_channels_(0),
      callback_(NULL),
       ipc_(ipc),
       stream_id_(0),
       play_on_start_(true),
      is_started_(false),
      audio_thread_(new AudioDeviceThread()) {
   CHECK(ipc_);
 }

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