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
auto command_line = base::CommandLine::ForCurrentProcess();
  base::FilePath exec_path(command_line->GetProgram());
  PathService::Get(base::FILE_EXE, &exec_path);
  base::FilePath resources_path =
#if defined(OS_MACOSX)
      is_browser ? exec_path.DirName().DirName().Append("Resources") :
                   exec_path.DirName().DirName().DirName().DirName().DirName()
                            .Append("Resources");
#else
      exec_path.DirName().Append(FILE_PATH_LITERAL("resources"));
#endif
  return resources_path;
}
}  
NodeBindings::NodeBindings(bool is_browser)
    : is_browser_(is_browser),
      message_loop_(nullptr),
      uv_loop_(uv_default_loop()),
      embed_closed_(false),
      uv_env_(nullptr),
      weak_factory_(this) {
}
NodeBindings::~NodeBindings() {