Speculative fix for timeout flakiness of hr-timestamp/input-events.html

Now call prevent default in event handler to ensure context menu does
not show up which can potentially hijack other events.

Added an explicit timeout to help produce more detailed picture when
timeout happens and hopefully help us identify the root cause if the
above fix is not working.

Also updated expectation to only expect timeout on Mac.


Bug: 846750, 846726
Change-Id: Ica117c5cd7eafc559c3e457af008d1a1043deff6
Reviewed-on: https://chromium-review.googlesource.com/1099039
Commit-Queue: Majid Valipour <majidvp@chromium.org>
Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566891}
2 files changed