- 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
if (parent_window_.IsEmpty())
    return v8::Null(isolate());
  else
    return v8::Local<v8::Value>::New(isolate(), parent_window_);
}
std::vector<v8::Local<v8::Object>> Window::GetChildWindows() const {
  return child_windows_.Values(isolate());
}
bool Window::IsModal() const {
  return window_->is_modal();
}
v8::Local<v8::Value> Window::GetNativeWindowHandle() {
  gfx::AcceleratedWidget handle = window_->GetAcceleratedWidget();
  return ToBuffer(
      isolate(), static_cast<void*>(&handle), sizeof(gfx::AcceleratedWidget));
}
void Window::SetVisibleOnAllWorkspaces(bool visible) {
  return window_->SetVisibleOnAllWorkspaces(visible);
}
bool Window::IsVisibleOnAllWorkspaces() {
  return window_->IsVisibleOnAllWorkspaces();
}
int32_t Window::ID() const {
  return weak_map_id();
}
v8::Local<v8::Value> Window::WebContents(v8::Isolate* isolate) {