[MemSheriff] Suppress crashing tests

NOTRY=true
TBR=thestig@chromium.org
BUG=315883

Review URL: https://codereview.chromium.org/59453003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233644 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233644