GitLab

Rather than including a fake alert object within the client accessibility tree, make the views tree include it with an explicit aura::Window.

TBR=servolk@chromium.org

Bug: 888152
Change-Id: I9e190a8e437a78c7e27ebfaab70ec20980dff32d
Reviewed-on: https://chromium-review.googlesource.com/c/1368828
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616064}