- 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
observers_.AddObserver(obs);
  }
  void RemoveObserver(NativeWindowObserver* obs) {
    observers_.RemoveObserver(obs);
  }
  brightray::InspectableWebContents* inspectable_web_contents() const {
    return inspectable_web_contents_;
  }
  bool has_frame() const { return has_frame_; }
  void set_has_frame(bool has_frame) { has_frame_ = has_frame; }
  bool transparent() const { return transparent_; }
  SkRegion* draggable_region() const { return draggable_region_.get(); }
  bool enable_larger_than_screen() const { return enable_larger_than_screen_; }
  NativeWindow* parent() const { return parent_; }
  bool is_modal() const { return is_modal_; }
 protected:
  NativeWindow(brightray::InspectableWebContents* inspectable_web_contents,
               const mate::Dictionary& options,
               NativeWindow* parent);
  
  
  std::unique_ptr<SkRegion> DraggableRegionsToSkRegion(
      const std::vector<DraggableRegion>& regions);
  
  virtual gfx::Rect ContentBoundsToWindowBounds(const gfx::Rect& bounds) = 0;
  virtual gfx::Rect WindowBoundsToContentBounds(const gfx::Rect& bounds) = 0;
  
  virtual void UpdateDraggableRegions(
      const std::vector<DraggableRegion>& regions);