* Electron version: 1.6.0
* Operating system: MacOS 10.12.2

### Expected behavior

'scroll-touch-end' emits when trackpad scrolling ends.

### Actual behavior

The begin event emits, but not the end

### How to reproduce

Example repo: https://github.com/pfrazee/electron-bug-no-scroll-touch-end

atom/browser/native_window.cc
#include "atom/browser/native_window.h"
#include <string>
#include <utility>
#include <vector>
#include "atom/browser/atom_browser_context.h"
#include "atom/browser/atom_browser_main_parts.h"
#include "atom/browser/browser.h"
#include "atom/browser/unresponsive_suppressor.h"
#include "atom/browser/window_list.h"
#include "atom/common/api/api_messages.h"
#include "atom/common/native_mate_converters/file_path_converter.h"
#include "atom/common/options_switches.h"
#include "base/files/file_util.h"
#include "base/json/json_writer.h"