Add content flag to ignore os input events

This helps tests to run only responding
to the synthetic inputs without os input
events interfering with the flow.

This first CL just ignores synthetic mouse
events on Aura platforms which conveys
mouse location to the newly openned windows.

Bug: 883710
Change-Id: I629c20ed3755462b45bf4a5b1ecc4075c3cba282
Reviewed-on: https://chromium-review.googlesource.com/c/1377727
Commit-Queue: Navid Zolghadr <nzolghadr@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620377}
4 files changed