SF: Introduce LayerSnapshot and LayerSnapshotBuilder
Create a builder that walks through the layer hierarchy
to build an ordered list of LayerSnapshots that can be
passed on to CompositionEngine.
This builder does a minimum amount of work to update
an existing set of snapshots based on hierarchy changes
and RequestedLayerState changes.
The builder also introduces a fast path to update
snapshots when there are only buffer updates.
Additionally, pull out LayerSnapshot class from LayerFE
and move it to frontend package.
Bug: 238781169
Test: presubmit
Change-Id: I3fbd6d60968950df2ee97d975c72f9e0aa31b007
19 files changed