- 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_mac.h
UpdateDraggableRegionViews(draggable_regions_);
  }
  
  void SetStyleMask(bool on, NSUInteger flag);
  void SetCollectionBehavior(bool on, NSUInteger flag);
  enum TitleBarStyle {
    NORMAL,
    HIDDEN,
    HIDDEN_INSET,
  };
  TitleBarStyle title_bar_style() const { return title_bar_style_; }
 protected:
  
  
  std::vector<gfx::Rect> CalculateNonDraggableRegions(
      const std::vector<DraggableRegion>& regions, int width, int height);
 private:
  
  gfx::Rect ContentBoundsToWindowBounds(const gfx::Rect& bounds);
  gfx::Rect WindowBoundsToContentBounds(const gfx::Rect& bounds);