Make scroll anchoring adjustment when the bounds of a scroller is changed
A layout update can change the bounds of a scroller, requiring us to clamp the
current scroll position if its outside the bounds of the scroller. This would
clear the saved scroll anchor and have a visible jump. The main issue is that
we would clear the anchor between ScrollAnchor::save and ScrollAnchor::restore.
This CL calls ::restore if clamping is needed to ensure that scroll anchoring
still works.
BUG=594876
Review-Url: https://codereview.chromium.org/2152773002
Cr-Commit-Position: refs/heads/master@{#406277}
3 files changed
