- 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
.SetMethod("isMovable", &Window::IsMovable)
      .SetMethod("setMinimizable", &Window::SetMinimizable)
      .SetMethod("isMinimizable", &Window::IsMinimizable)
      .SetMethod("setMaximizable", &Window::SetMaximizable)
      .SetMethod("isMaximizable", &Window::IsMaximizable)
      .SetMethod("setFullScreenable", &Window::SetFullScreenable)
      .SetMethod("isFullScreenable", &Window::IsFullScreenable)
      .SetMethod("setClosable", &Window::SetClosable)
      .SetMethod("isClosable", &Window::IsClosable)
      .SetMethod("setAlwaysOnTop", &Window::SetAlwaysOnTop)
      .SetMethod("isAlwaysOnTop", &Window::IsAlwaysOnTop)
      .SetMethod("center", &Window::Center)
      .SetMethod("setPosition", &Window::SetPosition)
      .SetMethod("getPosition", &Window::GetPosition)
      .SetMethod("setTitle", &Window::SetTitle)
      .SetMethod("getTitle", &Window::GetTitle)
      .SetMethod("flashFrame", &Window::FlashFrame)
      .SetMethod("setSkipTaskbar", &Window::SetSkipTaskbar)
      .SetMethod("setKiosk", &Window::SetKiosk)
      .SetMethod("isKiosk", &Window::IsKiosk)
      .SetMethod("setBackgroundColor", &Window::SetBackgroundColor)
      .SetMethod("setHasShadow", &Window::SetHasShadow)
      .SetMethod("hasShadow", &Window::HasShadow)
      .SetMethod("setRepresentedFilename", &Window::SetRepresentedFilename)
      .SetMethod("getRepresentedFilename", &Window::GetRepresentedFilename)
      .SetMethod("setDocumentEdited", &Window::SetDocumentEdited)
      .SetMethod("isDocumentEdited", &Window::IsDocumentEdited)
      .SetMethod("setIgnoreMouseEvents", &Window::SetIgnoreMouseEvents)
      .SetMethod("setContentProtection", &Window::SetContentProtection)
      .SetMethod("setFocusable", &Window::SetFocusable)