Add Ojan to web/OWNERS

I'm tired of rubberstamping CLs that he's already approved for this directory.

Review URL: https://codereview.chromium.org/26173004

git-svn-id: svn://svn.chromium.org/blink/trunk@159123 bbb929c8-8fbe-4397-9dbb-9b2b20218538