[DL]: Loosen the requirement for containment from content to style & layout

This patch ensures that we don't need paint containment to use display
locking. Updates all the tests to use the least needed containment
(style & layout)


Bug: 882663
Change-Id: I4deedb9f298cf63dd69dd0828420451e291684f0
Reviewed-on: https://chromium-review.googlesource.com/c/1396310
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621604}
30 files changed