* 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.cc
#include "atom/browser/api/atom_api_system_preferences.h"
#include "atom/common/native_mate_converters/callback.h"
#include "atom/common/native_mate_converters/value_converter.h"
#include "atom/common/node_includes.h"
#include "native_mate/dictionary.h"
#include "ui/gfx/color_utils.h"
namespace atom {
namespace api {
SystemPreferences::SystemPreferences(v8::Isolate* isolate)
#if defined(OS_WIN)
    : color_change_listener_(this)
#endif
    {
  Init(isolate);
#if defined(OS_WIN)
  InitializeWindow();
#endif
}
SystemPreferences::~SystemPreferences() {