Prevent generic motion event bleed through on the tab strip.

Right clicking on the tab strip would result in the page context
menu showing up from the underlying webpage. This is because
generic motion events are dispatched by ContentView before the
CompositorViewHolder could normally intercept.

This exposes generic motion events to scene layers to consume,
and for the AreaMotionEventFilter (used by the tab strip), this will
consume motion event types that would generate an action on
underlying layers.

Bug: 391719844
Change-Id: I22d94b161a1dc5308053be1a5ca9f6eb9254e29b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6427483
Reviewed-by: Aishwarya Rajesh <aishwaryarj@google.com>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1442295}