Enforce policy host restrictions in regard to the same-origin policy.

Bug: 774731
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I811af3256766f6cd7b4466b6b894067e74f652fd
Reviewed-on: https://chromium-review.googlesource.com/c/1050806
Commit-Queue: Nick Peterson <nrpeter@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599859}
31 files changed