- 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.h
void OnWindowMoved() override;
  void OnWindowScrollTouchBegin() override;
  void OnWindowScrollTouchEnd() override;
  void OnWindowSwipe(const std::string& direction) override;
  void OnWindowEnterFullScreen() override;
  void OnWindowLeaveFullScreen() override;
  void OnWindowEnterHtmlFullScreen() override;
  void OnWindowLeaveHtmlFullScreen() override;
  void OnRendererUnresponsive() override;
  void OnRendererResponsive() override;
  void OnExecuteWindowsCommand(const std::string& command_name) override;
  #if defined(OS_WIN)
  void OnWindowMessage(UINT message, WPARAM w_param, LPARAM l_param) override;
  #endif
 private:
  
  void Close();
  void Focus();
  void Blur();
  bool IsFocused();
  void Show();
  void ShowInactive();
  void Hide();
  bool IsVisible();
  bool IsEnabled();
  void Maximize();
  void Unmaximize();
  bool IsMaximized();
  void Minimize();
  void Restore();