Suppress a false positive leak report in Blink.

BUG=242672
TBR=glider@chromium.org

Review URL: https://codereview.chromium.org/88463002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237335 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237335