ozone: Add GamepadDevice to hold axis information

Linux's input_absinfo offers axis information of gamepad devices.
In order to improve gamepad support in ARC++, we need this information
in Exo. To do that, we have to subclass ui::InputDevice and add
ui::GamepadDevice. This is based on another example of subclassing
ui::InputDevice, which is ui::TouchscreenDevice.

Design doc: go/arc-improved-gamepad

TEST=manual
BUG=b:130597086

Change-Id: I7656740f77dce035856cc5a847472d5e10e0f1fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1624285
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Kevin Schoedel <kpschoedel@chromium.org>
Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Reviewed-by: Mitsuru Oshima (OOO 5/23) <oshima@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662970}
17 files changed