Add test for http://trac.webkit.org/changeset/136277

In studying RenderView::repaintViewAndCompositedLayers, we realized we were
missing test coverage for it. This CL tests that it's working properly.

R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/197073009

git-svn-id: svn://svn.chromium.org/blink/trunk@169204 bbb929c8-8fbe-4397-9dbb-9b2b20218538