Fix for <rdar://problem/4570475> Dashboard regions do not scale for 
        non-1.0 scale factors.

        No test cases added since this only affects non-1.0 resolution 
        scale factors.

        * platform/FloatRect.cpp:
        (WebCore::FloatRect::scale): Added new function that scales a 
        rect's origin and size by a given factor.
        * platform/FloatRect.h:
        * platform/IntRect.cpp:
        (WebCore::IntRect::scale): Same as above.
        * platform/IntRect.h:
        * rendering/RenderObject.cpp:
        (WebCore::RenderObject::addDashboardRegions): After the bounds and 
        clip rects on the Dashboard region have been calculated, get the 
        user space scale factor, and if it is not 1.0, scale the rects.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@14750 268f45cc-cd09-0410-ab3c-d52691b4dbfc