GitLab

Ensure that the members are fully cleaned up during disconnection,
before the object gets destroyed (which can happen on a random thread).
Otherwise the members may be destroyed on the wrong thread, triggering
DCHECKs.

BUG=395312

Review URL: https://codereview.chromium.org/406123002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284621 0039d316-1c4b-4281-b951-d872f2087c98