[Extensions Click-to-Script] Remove granted hosts when changing access

When transitioning from "on specific sites" to "on click", Chromium
should remove specific granted sites from the extension. Do so, and
add unittests for the same.

Bug: 844128

Change-Id: Icfa6c1f6449e94e30560a10cf43163f2fcedd996
Reviewed-on: https://chromium-review.googlesource.com/1133775
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574420}
2 files changed