Revert https://codereview.chromium.org/520433002

      This is a partial revert that removes the CORS checks.  All the other changes were in support of adding the 3 lines for the CORS checks to silence the output on failure.  Tests are also removed.

BUG=456312

Review URL: https://codereview.chromium.org/905023002

git-svn-id: svn://svn.chromium.org/blink/trunk@189724 bbb929c8-8fbe-4397-9dbb-9b2b20218538