- 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/native_window.cc
const std::vector<DraggableRegion>& regions) {
  
  if (has_frame_)
    return;
  draggable_region_ = DraggableRegionsToSkRegion(regions);
}
void NativeWindow::ScheduleUnresponsiveEvent(int ms) {
  if (!window_unresposive_closure_.IsCancelled())
    return;
  window_unresposive_closure_.Reset(
      base::Bind(&NativeWindow::NotifyWindowUnresponsive,
                 weak_factory_.GetWeakPtr()));
  base::MessageLoop::current()->PostDelayedTask(
      FROM_HERE,
      window_unresposive_closure_.callback(),
      base::TimeDelta::FromMilliseconds(ms));
}
void NativeWindow::NotifyWindowUnresponsive() {
  window_unresposive_closure_.Cancel();
  if (!is_closed_ && !IsUnresponsiveEventSuppressed() && IsEnabled())
    FOR_EACH_OBSERVER(NativeWindowObserver,
                      observers_,
                      OnRendererUnresponsive());
}
void NativeWindow::NotifyReadyToShow() {
  FOR_EACH_OBSERVER(NativeWindowObserver, observers_, OnReadyToShow());
}
}