- 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
#ifndef ATOM_BROWSER_NATIVE_WINDOW_MAC_H_
#define ATOM_BROWSER_NATIVE_WINDOW_MAC_H_
#import <Cocoa/Cocoa.h>
#include <string>
#include <vector>
#include "atom/browser/native_window.h"
#include "base/mac/scoped_nsobject.h"
#include "content/public/browser/render_widget_host.h"
@class AtomNSWindow;
@class AtomNSWindowDelegate;
@class FullSizeContentView;
namespace atom {
class NativeWindowMac : public NativeWindow,
                        public content::RenderWidgetHost::InputEventObserver {
 public:
  NativeWindowMac(brightray::InspectableWebContents* inspectable_web_contents,
                  const mate::Dictionary& options,
                  NativeWindow* parent);
  ~NativeWindowMac() override;
  
  void Close() override;
  void CloseImmediately() override;
  void Focus(bool focus) override;
  bool IsFocused() override;
  void Show() override;
  void ShowInactive() override;
  void Hide() override;
  bool IsVisible() override;