Initial refactoring to enable reuse of SkiaDisplayList
on a per RenderNode basis. With Skia renderer we
see 30% speed improvement in Invalidate Tree UI Jank test,
when SkiaDisplayList objects are reused.

Test: manually built and run on angler-eng.
Change-Id: Ie4ec50ddb2015150e3ec678dde7ebed0c8d90067
7 files changed