Reviewed by Mark Rowe.

        https://bugs.webkit.org/show_bug.cgi?id=24653
        WebKit should be buildable without prefix header injection.
        Adds missing #includes and forward declarations as needed.

        * editing/SmartReplaceCF.cpp:
        * platform/graphics/mac/ColorMac.mm:
        * platform/graphics/mac/FontCacheMac.mm:
        * platform/graphics/mac/FontCustomPlatformData.h:
        * platform/graphics/mac/FontMac.mm:
        * platform/graphics/mac/FontMacATSUI.mm:
        * platform/graphics/mac/FontPlatformData.h:
        * platform/graphics/mac/FontPlatformDataMac.mm:
        * platform/graphics/mac/GraphicsContextMac.mm:
        * platform/graphics/mac/SimpleFontDataMac.mm:
        * platform/mac/FoundationExtras.h:
        * platform/mac/LocalCurrentGraphicsContext.h:
        * platform/mac/WebCoreSystemInterface.h:
        * platform/mac/WebCoreSystemInterface.mm:
        * platform/mac/WebCoreTextRenderer.h:
        * platform/mac/WebCoreTextRenderer.mm:
        * platform/mac/WebFontCache.h:
        * platform/mac/WebFontCache.mm:
        * platform/text/PlatformString.h:
        * platform/text/mac/ShapeArabic.c:
        * platform/text/mac/StringMac.mm:
        * rendering/RenderThemeChromiumMac.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@41939 268f45cc-cd09-0410-ab3c-d52691b4dbfc