add OWNERS file

BUG=none
R=aruslan@chromium.org

Review URL: https://codereview.chromium.org/114033006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243403 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243403