Add more directories to _CheckForString16() whitelist.

TBR=joi@chromium.org
BUG=329295
NOTRY=true

Review URL: https://codereview.chromium.org/119763003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242052 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242052