GitLab

Destruction order should be harmless, but should be cleaned up. CHECKs
should tell us if the controller is being shutdown while callbacks are in flight.

BUG=349651
TEST=none

Review URL: https://codereview.chromium.org/188243002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255757 0039d316-1c4b-4281-b951-d872f2087c98