GitLab

This fixes a crash that shows up when terminating from the system tray popup.

BUG=105151,124310
TEST=WidgetObserverTest.DestroyBubble

Review URL: https://chromiumcodereview.appspot.com/10204014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133748 0039d316-1c4b-4281-b951-d872f2087c98