Enable ForceCompositingMode in media/ tests that have different output.

This rebaselines the tests in media/ that change their pixel output
when ForceCompositingMode is turned on, by turning it on for the
individual tests.

The pixel differences are all different sampling for scaling, and
non-visible pixel differences.

R=enne
BUG=361729

Review URL: https://codereview.chromium.org/268683005

git-svn-id: svn://svn.chromium.org/blink/trunk@173130 bbb929c8-8fbe-4397-9dbb-9b2b20218538