Show the confirm-to-quit bubble on the active browser window's screen

The bubble used to always show on the primary monitor.  This looked odd when
there was a browser window open only on a secondary monitor.

This CL changes the bubble to show on the same monitor as the last active
browser window.

BUG=243164
R=sky

Change-Id: I439f6c873bace728a39fe1f93728590a47f083be
Reviewed-on: https://chromium-review.googlesource.com/1072274
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562502}
1 file changed