Convert most of fast/repaint to use text based harness

The pixel-based repaint test harness is incompatible with compositing and
has to go.  The text-based harness can test everything that the pixel based version could.

This converts almost everything over by switching tests using f/r/resources/repaint.js
over to f/r/resources/text-based-repaint.js, fixes up a few tests to work, and
converts a few tests that are actually just pixel tests (not repaint tests) to
do only what they need to do to cover what they intend to cover.

BUG=344105

Review URL: https://codereview.chromium.org/168243002

git-svn-id: svn://svn.chromium.org/blink/trunk@167542 bbb929c8-8fbe-4397-9dbb-9b2b20218538