fix mocking of various files in webkit_unit_tests

so that https://codereview.chromium.org/17229012 doesn't dcheck.

R=jamesr@chromium.org
BUG=237267

Review URL: https://chromiumcodereview.appspot.com/16831015

git-svn-id: svn://svn.chromium.org/blink/trunk@152760 bbb929c8-8fbe-4397-9dbb-9b2b20218538
4 files changed