Steps to reproduce the problem:
Load a remote DevTools front-end in a webview (same Electron version on both ends)

What is the expected behavior?
Remote DevTools is opened in the webview

What went wrong?
"Uncaught TypeError: Cannot read property 'extensions' of undefined".
At this point, it tries to access window.runtime.extensions("settings").
See screenshot.

Did this work before? Yes 51.0.2704.63

Chrome version: 52.0.2743.82
OS Version: OS X 10.11.4

Worked fine until Electron 1.2.0 (Chromium 51.0.2704.63) with the disablewebsecurity attribute set. Broken on 1.2.1.
Current chromium version (1.3.0): 52.0.2743.82

![screen shot 2016-07-25 at 5 36 13 pm](https://cloud.githubusercontent.com/assets/1028286/17125639/1a265cce-52aa-11e6-8413-2d75c642dbb2.png)

atom/common/node_bindings.cc
DCHECK(message_loop_);
  message_loop_->PostTask(FROM_HERE, base::Bind(&NodeBindings::UvRunOnce,
                                                weak_factory_.GetWeakPtr()));
}
void NodeBindings::WakeupEmbedThread() {
  uv_async_send(&dummy_uv_handle_);
}
void NodeBindings::EmbedThreadRunner(void *arg) {
  NodeBindings* self = static_cast<NodeBindings*>(arg);
  while (true) {
    
    uv_sem_wait(&self->embed_sem_);
    if (self->embed_closed_)
      break;
    
    
    
    
    
    self->PollEvents();
    if (self->embed_closed_)
      break;
    
    self->WakeupMainThread();
  }
}
}