Portals navigation throttle for 1P mode.

When enabled, this provides browser-side enforcement precluding navigations
in a portal to any origin other than the origin of its host.

Bug: 1013389
Change-Id: Ia7b2a94463b3fb4ba68fcf63f0e6e56342ca20ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854150
Commit-Queue: Jeremy Roman <[email protected]>
Reviewed-by: Kinuko Yasuda <[email protected]>
Reviewed-by: Kevin McNee <[email protected]>
Cr-Commit-Position: refs/heads/master@{#708249}
8 files changed