* 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
return sheet_offset_x_;
}
double NativeWindow::GetSheetOffsetY() {
  return sheet_offset_y_;
}
void NativeWindow::SetRepresentedFilename(const std::string& filename) {
}
std::string NativeWindow::GetRepresentedFilename() {
  return "";
}
void NativeWindow::SetDocumentEdited(bool edited) {
}
bool NativeWindow::IsDocumentEdited() {
  return false;
}
void NativeWindow::SetFocusable(bool focusable) {
}
void NativeWindow::SetMenu(AtomMenuModel* menu) {
}
void NativeWindow::SetParentWindow(NativeWindow* parent) {
  parent_ = parent;
}
void NativeWindow::SetAutoHideCursor(bool auto_hide) {
}
void NativeWindow::SetVibrancy(const std::string& filename) {
}
void NativeWindow::FocusOnWebView() {
  web_contents()->GetRenderViewHost()->GetWidget()->Focus();
}
void NativeWindow::BlurWebView() {