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
v8::Handle<v8::Context> context) {
  auto args = AtomCommandLine::argv();
  
  base::FilePath::StringType process_type = is_browser_ ?
      FILE_PATH_LITERAL("browser") : FILE_PATH_LITERAL("renderer");
  base::FilePath resources_path = GetResourcesPath(is_browser_);
  base::FilePath script_path =
      resources_path.Append(FILE_PATH_LITERAL("electron.asar"))
                    .Append(process_type)
                    .Append(FILE_PATH_LITERAL("init.js"));
  std::string script_path_str = script_path.AsUTF8Unsafe();
  args.insert(args.begin() + 1, script_path_str.c_str());
  std::unique_ptr<const char*[]> c_argv = StringVectorToArgArray(args);
  node::Environment* env = node::CreateEnvironment(
      context->GetIsolate(), uv_default_loop(), context,
      args.size(), c_argv.get(), 0, nullptr);
  mate::Dictionary process(context->GetIsolate(), env->process_object());
  process.Set("type", process_type);
  process.Set("resourcesPath", resources_path);
  
  if (!is_browser_)
    process.Set("_noBrowserGlobals", resources_path);
  
  base::FilePath helper_exec_path;
  PathService::Get(content::CHILD_PROCESS_EXE, &helper_exec_path);
  process.Set("helperExecPath", helper_exec_path);
  return env;
}
void NodeBindings::LoadEnvironment(node::Environment* env) {