cc: Don't mark any tilings low resolution during animation/pinch.
This patch ensures that while we're animating or pinching, we not only
not create low resolution tilings (which was already the case), but we
also don't mark any existing tilings as low resolution.
If we do, this can cause checker flashes when low res becomes high res
again, since we have to reset it due to low quality filters that might
have been applied.
BUG=517749
R=danakj, enne
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/
1296453002
Cr-Commit-Position: refs/heads/master@{#343299}