GitLab

Crash reports indicate that the EventDispatchDetails might actually be
wrong sometimes and that the EventProcessor is destroyed.

Add a weak ptr to trap the destruction of the current object.

BUG=763372

Change-Id: I5fec449221c962a6ce755cd3c69e62c2a0d3af9a
Reviewed-on: https://chromium-review.googlesource.com/658019Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#504194}