- Electron version: v1.3.3
- Operating system: OS X 10.11.6

v1.3.3 broke the detection of the `scroll-touch-begin` and `scroll-touch-end` events for me within a `webview`. It looks like the pull request #6754 caused this issue. v1.3.2 works as expected.

Behavior that I'm observing on v1.3.3:
- Most of the time, the `scroll-touch-*` events are not emitted when the cursor is on top of a `webview`.
- The `scroll-touch-*` events seem to be emitted _only once_ when the cursor is on a `webview` and on a scrollable element. The scrollable elements in my app have no native scrollbar set (they have the style `overflow: hidden;` set instead of `overflow: scroll;`). This is the case in which I need to receive the `scroll-touch-*` events.
- The `scroll-touch-*` events seem to work fine when the cursor is outside of the `webview` tag.

atom/browser/api/atom_api_window.cc
#if defined(OS_WIN)
  std::vector<TaskbarHost::ThumbarButton> buttons;
  if (!args->GetNext(&buttons)) {
    args->ThrowError();
    return false;
  }
  auto window = static_cast<NativeWindowViews*>(window_.get());
  return window->taskbar_host().SetThumbarButtons(
      window_->GetAcceleratedWidget(), buttons);
#else
  return false;
#endif
}
void Window::SetMenu(v8::Isolate* isolate, v8::Local<v8::Value> value) {
  mate::Handle<Menu> menu;
  if (value->IsObject() &&
      mate::V8ToString(value->ToObject()->GetConstructorName()) == "Menu" &&
      mate::ConvertFromV8(isolate, value, &menu)) {
    menu_.Reset(isolate, menu.ToV8());
    window_->SetMenu(menu->model());
  } else if (value->IsNull()) {
    menu_.Reset();
    window_->SetMenu(nullptr);
  } else {
    isolate->ThrowException(v8::Exception::TypeError(
        mate::StringToV8(isolate, "Invalid Menu")));
  }
}
void Window::SetAutoHideMenuBar(bool auto_hide) {