GitLab

Define GestureDevice, InertialPhaseState, Button, DispatchType
in mojom. This allows the removal of the typemappings.
TBR=avi@chromium.org

Change-Id: Iefe74aebbb49d3155c8cc2f36282575d0b879276
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152777
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760204}