Make RunLoop remove handle when a timeout is notified

BUG=None
TEST=Added to existing tests
R=sky

Review URL: https://codereview.chromium.org/126883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243467 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243467