Track CSP-set sandbox flags separately from frame owner flags

Bug: 740556
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
Change-Id: If696428160446e636eaa1a9fa3ef7e067b0c8922
Reviewed-on: https://chromium-review.googlesource.com/712711
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Alex Moshchuk <[email protected]>
Commit-Queue: Ian Clelland <[email protected]>
Cr-Commit-Position: refs/heads/master@{#519420}
44 files changed