Fix for 4638376. The 1x1 solid color image optimization was broken when

    Fix for 4638376.  The 1x1 solid color image optimization was broken when
        I re-architected image.  This patch restores the optimization for CG.  Cairo
        will still need the optimization.

        Reviewed by darin

        WARNING: NO TEST CASES ADDED OR CHANGED (need test cases still)

        * platform/Image.cpp:
        (WebCore::Image::Image):
        (WebCore::Image::invalidateData):
        (WebCore::Image::cacheFrame):
        * platform/Image.h:
        (WebCore::Image::setIsPDF):
        * platform/cairo/ImageCairo.cpp:
        (WebCore::Image::checkForSolidColor):
        * platform/mac/ImageMac.mm:
        (WebCore::Image::initNativeData):
        (WebCore::Image::invalidateNativeData):
        (WebCore::Image::checkForSolidColor):
        (WebCore::Image::draw):
        (WebCore::Image::drawTiled):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@15529 268f45cc-cd09-0410-ab3c-d52691b4dbfc