- 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/api/atom_api_window.cc
Emit("maximize");
}
void Window::OnWindowUnmaximize() {
  Emit("unmaximize");
}
void Window::OnWindowMinimize() {
  Emit("minimize");
}
void Window::OnWindowRestore() {
  Emit("restore");
}
void Window::OnWindowResize() {
  Emit("resize");
}
void Window::OnWindowMove() {
  Emit("move");
}
void Window::OnWindowMoved() {
  Emit("moved");
}
void Window::OnWindowEnterFullScreen() {
  Emit("enter-full-screen");
}
void Window::OnWindowLeaveFullScreen() {
  Emit("leave-full-screen");
}
void Window::OnWindowScrollTouchBegin() {
  Emit("scroll-touch-begin");
}
void Window::OnWindowScrollTouchEnd() {