Add haptics for X360 and Xbox One gamepads on Mac

On Mac, Xbox gamepads connected over USB are supported by an internal
driver that is used when no OS-level driver is installed. This CL adds
haptics support for Xbox gamepads connected in this way.

BUG=749295

Change-Id: Ie674b0b832ad0f1922821c3f9ef1ce232ab2dcd0
Reviewed-on: https://chromium-review.googlesource.com/754366
Reviewed-by: Brandon Jones <bajones@chromium.org>
Commit-Queue: Matt Reynolds <mattreynolds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516047}
4 files changed