GitLab

After we finish the scroll unification, the scrolls happens mainly on
the compositor thread, and the scroll code in the main thread will be
removed. eventSender sends the scroll events to main thread, so it
would not work after the scroll unification. We should replace
eventSender.mouseScrollBy with gpuBenchmarking.smoothScrollBy
in all the layout tests, this is part 1.

Bug: 1047176
Change-Id: If746d2b7a4b0a031829105115d9c27d46a27cfa4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2119532
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759417}