* Electron version: 1.4.4
* Operating system: win10

Hi,
Example described [here](https://github.com/electron/electron/blob/master/docs/api/global-shortcut.md) works with v1.4.0 but doesn't seem to work with v1.4.4 or v1.4.5.  Method `globalShortcut.isRegistered ` returns true, but the callback isn't called. 

Thanks!
atom/browser/api/atom_api_system_preferences_win.cc
UINT message,
                                        WPARAM wparam,
                                        LPARAM lparam) {
  if (message == WM_DWMCOLORIZATIONCOLORCHANGED) {
    DWORD new_color = (DWORD) wparam;
    std::string new_color_string = hexColorDWORDToRGBA(new_color);
    if (new_color_string != current_color_) {
      Emit("accent-color-changed", hexColorDWORDToRGBA(new_color));
      current_color_ = new_color_string;
    }
  }
  return ::DefWindowProc(hwnd, message, wparam, lparam);
}
void SystemPreferences::OnSysColorChange() {
  bool new_invertered_color_scheme = IsInvertedColorScheme();
  if (new_invertered_color_scheme != invertered_color_scheme_) {
    invertered_color_scheme_ = new_invertered_color_scheme;
    Emit("inverted-color-scheme-changed", new_invertered_color_scheme);
  }
  Emit("color-changed");
}
}  
}