Reviewed by Maciej.
Fix for <rdar://problem/4616595> REGRESSION: Problems with world clock widget clock hand motion on 9A211 + 4604574 The second hand on the widget was jiggling because the rotation was messing up the use of the affine transformation matrix while rounding to pixel boundaries in device space. We are mainly concerned with rounding to pixel boundaries with the scale in mind, so this patch extracts the scale to device space from the matrix, and rounds to pixel boundaries using only the scale. This doesn't seem like it is a perfect solution, but it definitely solves the immediate problem. We will probably need to re-address what should happen to avoid pixel cracks with rotations at non-integral scale factors. * platform/cg/GraphicsContextCG.cpp: (WebCore::GraphicsContext::roundToDevicePixels): git-svn-id: http://svn.webkit.org/repository/webkit/trunk@15470 268f45cc-cd09-0410-ab3c-d52691b4dbfc