Handle CC position change from safe_area_inset_bottom

(1) Add new composition flags for supporting SAI in CC.
  CompositingReason::kAffectedBySafeAreaBottom
  compositor_node.moved_by_safe_area_bottom
  transform_tree.nodes_affected_by_safe_area_inset_bottom
These flags are set according to
ComputedStyle::IsBottomRelativeToSafeAreaInset() in Blink.

(2) Plumb |moved_by_safe_area_bottom| and |nodes_affected_by_safe_area_inset_bottom| from Blink to CC.

(3) Calculate and apply the transform y adjustment in CC.

This new feature is put behind the feature flag DynamicSafeAreaInsetsSupportedByCC, and it's disabled by default.

Bug:373980016

Change-Id: I6f9bcd09020b3f1c65246cb4567fa82884a47d0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6066002
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Maggie Chen <magchen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1394502}