Reviewed by Oliver Hunt.

        Canvas: Move fillRect() save/restore into GraphicsContext implementations
        https://bugs.webkit.org/show_bug.cgi?id=42088

        Saving the platform painter state is an expensive operation,
        so don't do it in fillRect() for platforms that don't need it. (CG, Qt)

        * html/canvas/CanvasRenderingContext2D.cpp:
        (WebCore::CanvasRenderingContext2D::fillRect):
        * platform/graphics/cairo/GraphicsContextCairo.cpp:
        (WebCore::GraphicsContext::fillRect):
        * platform/graphics/skia/GraphicsContextSkia.cpp:
        (WebCore::GraphicsContext::fillRect):
        * platform/graphics/wince/GraphicsContextWince.cpp:
        (WebCore::GraphicsContext::fillRect):
        * platform/graphics/wx/GraphicsContextWx.cpp:
        (WebCore::GraphicsContext::fillRect):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@63102 268f45cc-cd09-0410-ab3c-d52691b4dbfc