Make inverted viewport scroll order the default and remove flag.
This patch removes the invert-viewport-scroll-order flag, making this behavior
the default. This means scrolls while pinch-zoomed in scroll the visual viewport
first, bubbling remaining scrolls up to the layout viewport. Also fixed existing
unit tests that relied on the old behavior.
BUG=443724
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
Review URL: https://codereview.chromium.org/
1283053002
Cr-Commit-Position: refs/heads/master@{#345636}