We have an incorrect check in DrawingAreaImpl constructor that has never actually worked because it uses the page settings before they were initialized. But that has been fixed in r197409 and now we are always forcing accelerated compositing mode incorrectly, because m_alwaysUseCompositing is set in the constructor and never changed again.
Created attachment 272658 [details]
Please, review this, *all* the tests in our bots are currently broken
Created attachment 272659 [details]
Sorry, I submitted the wrong patch by mistake.
Committed r197452: <http://trac.webkit.org/changeset/197452>