Delete all low-level rendering from ccpr

This converts ccpr to just a poorly named atlas manager. The atlas
gets rendered by normal calls on its MSAA draw context:

  for (;;) {
      surfaceDrawContext->stencilPath();  // Stencil.
  }
  surfaceDrawContext->stencilRect(atlasBounds);  // Cover.

Bug: chromium:1158093
Change-Id: I758ffd372b2ed5bb8b370156b6f80f6204146700
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/381618
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
31 files changed