GitLab

Switch access should only use KeyEvents from physical keyboards as
switches; virtual keyboard events should be ignored.

Added a browser test for SwitchAccess

BUG=864802

Change-Id: Ia50bacafe0c0740b4eea6c9f290c8679b61d79bc
Reviewed-on: https://chromium-review.googlesource.com/1114069Reviewed-by: David Tseng <dtseng@chromium.org>
Reviewed-by: Katie Dektar <katie@chromium.org>
Commit-Queue: Zach Helfinstein <zhelfins@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580321}