GitLab

Adds Allowed/Committed PreviewsState -> PreviewType support in
PreviewsContentUtil for DeferAllScript preview. It is prioritized
at this level above ResourceLoadingHints and NoScript since they are
supported on older clients and also assuming it is a better option
if supported by the client. The optimization guide logic may affect
priority separately as well.

Bug: 965277
Change-Id: I27b24ad4076f9b424cc9c5041e2d7a36027b12f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1669983
Commit-Queue: Doug Arnett <dougarnett@chromium.org>
Reviewed-by: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#671878}