- 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.h
content::WebContents*,
      const content::NativeWebKeyboardEvent& event) {}
  
  
  void NotifyWindowClosed();
  void NotifyWindowBlur();
  void NotifyWindowFocus();
  void NotifyWindowShow();
  void NotifyWindowHide();
  void NotifyWindowMaximize();
  void NotifyWindowUnmaximize();
  void NotifyWindowMinimize();
  void NotifyWindowRestore();
  void NotifyWindowMove();
  void NotifyWindowResize();
  void NotifyWindowMoved();
  void NotifyWindowScrollTouchBegin();
  void NotifyWindowScrollTouchEnd();
  void NotifyWindowSwipe(const std::string& direction);
  void NotifyWindowEnterFullScreen();
  void NotifyWindowLeaveFullScreen();
  void NotifyWindowEnterHtmlFullScreen();
  void NotifyWindowLeaveHtmlFullScreen();
  void NotifyWindowExecuteWindowsCommand(const std::string& command);
  #if defined(OS_WIN)
  void NotifyWindowMessage(UINT message, WPARAM w_param, LPARAM l_param);
  #endif
  void AddObserver(NativeWindowObserver* obs) {