nodeAtPoint(): Perform the early-check EARLY.
Hit-testing overflow controls before checking if we need to do anything at all
affected performance, so just remove the LayoutBlock override for nodeAtPoint()
and hit test overflow controls there, but do so AFTER we have made sure that
the point is within bounds.
Fixes 15% performance regression for
PerformanceTests/Events/hit-test-lots-of-layers.html
BUG=610250
Review-Url: https://codereview.chromium.org/1960373002
Cr-Commit-Position: refs/heads/master@{#392626}
4 files changed
