Make PaintInvalidation a DocumentLifecyle state

PaintInvalidation is run for every frame so it makes sense to
move it to be a first class citizen of our state machine.

Review URL: https://codereview.chromium.org/406743002

git-svn-id: svn://svn.chromium.org/blink/trunk@178603 bbb929c8-8fbe-4397-9dbb-9b2b20218538