* 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
for (NativeWindowObserver& observer : observers_)
    observer.OnWindowMinimize();
}
void NativeWindow::NotifyWindowRestore() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowRestore();
}
void NativeWindow::NotifyWindowResize() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowResize();
}
void NativeWindow::NotifyWindowMove() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowMove();
}
void NativeWindow::NotifyWindowMoved() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowMoved();
}
void NativeWindow::NotifyWindowEnterFullScreen() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowEnterFullScreen();
}
void NativeWindow::NotifyWindowScrollTouchBegin() {
  for (NativeWindowObserver& observer : observers_)
    observer.OnWindowScrollTouchBegin();
}
void NativeWindow::NotifyWindowScrollTouchEnd() {