Widen one TSan v2 suppression

Also, nuke the empty tools/heapcheck directory -- I couldn't do that as a separate CL as the directory is empty.
BUG=244383,325380
TBR=oshima@chromium.org

Review URL: https://codereview.chromium.org/182983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253756 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253756