Get rid of one-off paint invalidation code for paints-into-ancestor compositing state.

Instead use the same paths as other compositing updates.


BUG=384520

Review URL: https://codereview.chromium.org/358153003

git-svn-id: svn://svn.chromium.org/blink/trunk@177157 bbb929c8-8fbe-4397-9dbb-9b2b20218538