Composite to cc::Display from ui::InProcessContextFactory.

The trees this composites may contain SurfaceLayers, so they have to be aggregated into a Display before being drawn. Also move OnscreenDisplayClient and SurfaceDisplayOutputSurface into cc/surfaces/ so they can be used by ui/compositor.

Review URL: https://codereview.chromium.org/888783002

Cr-Commit-Position: refs/heads/master@{#314269}
20 files changed