Using TextureMapper, the only place where repaint rects are being tracked is in GraphicsLayer.
The FrameView does not know about any repaint rects in this case.
Therefore dumping from the FrameView is not generating the expected result.
This test case will always have a semi transparent dark layer on top because no repaint rects are detected.
Committed r140130: <http://trac.webkit.org/changeset/140130>
Accidentially closed by skipping the test.
The QT port is no longer part of WebKit.