Rename repaint to paintInvalidation in core/rendering/svg.

This CL renames all of the repaint methods in core/rendering/svg to be
paintInvalidation.

BUG=338691

Review URL: https://codereview.chromium.org/463883003

git-svn-id: svn://svn.chromium.org/blink/trunk@180136 bbb929c8-8fbe-4397-9dbb-9b2b20218538