Gardening: Correct expectations for compositing/rtl/rtl-iframe-*.html.
Gardening: Correct expectations for compositing/rtl/rtl-iframe-*.html.

BUG=192172,227473

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@147779 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs