Shipping embedded enforcement

Spec: https://w3c.github.io/webappsec-csp/embedded/
I2I: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/bck8mCc-HOQ
I2S: https://groups.google.com/a/chromium.org/d/msg/blink-dev/DdzeM55D87Y/kwMlfu-DBgAJ

Bug: 647588
Change-Id: I33406dc0e61059cf2b0a4a26c50572a9ff189735
Reviewed-on: https://chromium-review.googlesource.com/525693
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Reviewed-by: Mike West <mkwst@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Andy Paicu <andypaicu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477604}
4 files changed