Rename repaint to paintInvalidation in rendering/style.

This CL updates the usage of repaint to be paintInvalidation inside the
various style/ classes.

BUG=338691

Review URL: https://codereview.chromium.org/470633002

git-svn-id: svn://svn.chromium.org/blink/trunk@180192 bbb929c8-8fbe-4397-9dbb-9b2b20218538