Revert of Fix several corner case issues of scrollbar paint invalidation (patchset #7 id:120001 of https://codereview.chromium.org/1491193003/ )
Reason for revert:
I suspect this may have broken the Oilpan build:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac%20Oilpan/builds/27442
Original issue's description:
> Fix several corner case issues of scrollbar paint invalidation
>
> - Invalidate composited scrollbars also during paint invalidation to
> avoid unnecessary invalidation on intermediate changes;
>
> - Invalidate also on the containing box for moved/resized composited
> non-overlay scrollbars. This ensures the expanded/shrunk areas of the
> box because of scrollbar existence/width change are invalidated. This
> is the root cause of bug 535161.
>
> - Avoid unnecessary invalidations on overlay scrollbar changes.
>
> BUG=535161,560418
>
> Committed: https://crrev.com/48e402acbebf2717b8e79b89dba5310d31bf95da
> Cr-Commit-Position: refs/heads/master@{#363998}
TBR=chrishtr@chromium.org,skobes@chromium.org,wangxianzhu@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=535161,560418
Review URL: https://codereview.chromium.org/1513573004
Cr-Commit-Position: refs/heads/master@{#364000}
23 files changed
