Add querySurfacePointerANGLE method to Surface. This method will more closely match the desktop GL implementation. BUG=angle:795 Change-Id: I796b46bb6e8e895dad8d9824e8405edcc12e8a4f Reviewed-on: https://chromium-review.googlesource.com/228915 Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>