GitLab

This was causing an intermittent crash in the SelectionClear unit
tests, since it cleared the TARGETS atom out of the list of offered
types

BUG=none

Review URL: https://codereview.chromium.org/129763002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243985 0039d316-1c4b-4281-b951-d872f2087c98