suppress data race at me2me_native_messaging_host.cc
BUG=328521
TBR=weitaosu@chromium.org
TEST=waterfall.sh

Review URL: https://codereview.chromium.org/115413004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240749 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240749