Hooked in the reporting api changes into content layer CSP

The work for reporting has already been done, this only pipes into the
content layer CSP the relevant info and then pipes it back down to
webkit CSP when reports need to be submitted.

Reporting spec: https://wicg.github.io/reporting/

Related: https://chromium-review.googlesource.com/c/chromium/src/+/629083

Bug: 726634
Change-Id: I5d598840e3170fc91de4f9169b66774cbe407ede
Reviewed-on: https://chromium-review.googlesource.com/788855
Commit-Queue: Andy Paicu <andypaicu@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532840}
17 files changed