Split SwapChainPresenter and DCLayerTree into their own files.

Currently they are part of direct_composition_surface_win.cc, but
they are complicated enough to be in their own files. This also
makes code reading and code review much easier.

This is pure refactoring.

BUG=955232
TEST=win bots
R=sunnyps@chromium.org

Change-Id: Ia76f0ddb55d6dc0840b334b94194f6fba13f3ef1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1578208
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Maggie Chen <magchen@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653450}
7 files changed