Remove bogus DEPS entry

There's no reason to list "android" as a valid DEPS entry for WTF. When
including system header, the correct style is to use angle brackets, which
placates the DEPS checker.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/26228002

git-svn-id: svn://svn.chromium.org/blink/trunk@159020 bbb929c8-8fbe-4397-9dbb-9b2b20218538