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
REFERENCE_MODULE(atom_browser_menu);
REFERENCE_MODULE(atom_browser_power_monitor);
REFERENCE_MODULE(atom_browser_power_save_blocker);
REFERENCE_MODULE(atom_browser_protocol);
REFERENCE_MODULE(atom_browser_global_shortcut);
REFERENCE_MODULE(atom_browser_render_process_preferences);
REFERENCE_MODULE(atom_browser_session);
REFERENCE_MODULE(atom_browser_system_preferences);
REFERENCE_MODULE(atom_browser_tray);
REFERENCE_MODULE(atom_browser_web_contents);
REFERENCE_MODULE(atom_browser_web_view_manager);
REFERENCE_MODULE(atom_browser_window);
REFERENCE_MODULE(atom_common_asar);
REFERENCE_MODULE(atom_common_clipboard);
REFERENCE_MODULE(atom_common_crash_reporter);
REFERENCE_MODULE(atom_common_native_image);
REFERENCE_MODULE(atom_common_screen);
REFERENCE_MODULE(atom_common_shell);
REFERENCE_MODULE(atom_common_v8_util);
REFERENCE_MODULE(atom_renderer_ipc);
REFERENCE_MODULE(atom_renderer_web_frame);
#undef REFERENCE_MODULE
#if defined(OS_WIN) && !defined(DEBUG)
namespace v8 {
const int Function::kLineOffsetNotFound = -1;
}
#endif
namespace atom {
namespace {
void UvNoOp(uv_async_t* handle) {