Reviewed by Darin.

        - http://bugs.webkit.org/show_bug.cgi?id=13320
          rounded corners with drop shadows are really slow

        Test for a rendering bug fixed by this patch:
            fast/box-shadow/border-radius-big.html

        No test for the performance ingredient.

        * platform/graphics/GraphicsContext.cpp:
        (WebCore::GraphicsContext::addRoundedRectClip): Made cross-platform.
        Changed to use a single clipping path. If all the radii cannot be
        accommodated, clips to a rect.
        (WebCore::GraphicsContext::clipOutRoundedRect): Changed to use a single
        clipping path. If all the radii cannot be accommodated, clips out a rect.
        * platform/graphics/GraphicsContext.h: Added clipOut(const Path&).
        * platform/graphics/Path.cpp:
        (WebCore::Path::createRoundedRectangle): Added. Returns a rounded rectangle
        with the specified radii. If all the radii cannot be accommodated, returns
        a rectangular path.
        * platform/graphics/Path.h:
        * platform/graphics/cairo/GraphicsContextCairo.cpp:
        (WebCore::GraphicsContext::clipOut): Added.
        * platform/graphics/cg/GraphicsContextCG.cpp:
        (WebCore::GraphicsContext::fillRoundedRect): Changed to use a single path.
        (WebCore::GraphicsContext::clipOut): Added.
        * platform/graphics/qt/GraphicsContextQt.cpp:
        (WebCore::GraphicsContext::clipOut): Added.

2007-05-19  Mitz Pettel  <mitz@webkit.org>

        Reviewed by Darin.

        - http://bugs.webkit.org/show_bug.cgi?id=13320
          rounded corners with drop shadows are really slow

        * fast/box-shadow/border-radius-big-expected.checksum: Added.
        * fast/box-shadow/border-radius-big-expected.png: Added.
        * fast/box-shadow/border-radius-big-expected.txt: Added.
        * fast/box-shadow/border-radius-big.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@21601 268f45cc-cd09-0410-ab3c-d52691b4dbfc