Reviewed by Maciej.

WebCore:
        Adding RetainPtr to the many global obj-c pointers we use in
        C/C++ methods.  This is necessary to prevent GC from collecting
        globals we want to keep around.

        We use RetainPtr in obj-c++ and c++ files, and CFRetain/Release in pure
        obj-c.

        Also made the Pasteboard::m_pasteboard a RetainPtr although it
        shouldn't be necessary as the only NSPasteboard instances that 
        should ever be inserted are the system clipboard and dragging 
        pasteboard.  Neither of which should ever be collected.

        * page/mac/WebCoreFrameBridge.mm:
        (_getPreSmartSet):
        (_getPostSmartSet):
        * platform/Pasteboard.h:
        * platform/graphics/mac/ColorMac.mm:
        (WebCore::nsColor):
        * platform/graphics/mac/GraphicsContextMac.mm:
        (WebCore::GraphicsContext::drawLineForMisspellingOrBadGrammar):
        * platform/mac/FontDataMac.mm:
        (WebCore::webFallbackFontFamily):
        * platform/mac/PasteboardMac.mm:
        (WebCore::writableTypesForURL):
        (WebCore::writableTypesForImage):
        (WebCore::Pasteboard::clear):
        (WebCore::Pasteboard::writeSelection):
        (WebCore::Pasteboard::writeURL):
        (WebCore::Pasteboard::writeFileWrapperAsRTFDAttachment):
        (WebCore::Pasteboard::writeImage):
        (WebCore::Pasteboard::canSmartReplace):
        (WebCore::Pasteboard::plainText):
        (WebCore::Pasteboard::documentFragment):

WebKit:
        Adding RetainPtr to the many global obj-c pointers we use in
        C/C++ methods.  This is necessary to prevent GC from collecting
        globals we want to keep around.

        We use RetainPtr in obj-c++ and c++ files, and CFRetain/Release in pure
        obj-c.

        This fixes <rdar://problem/5058731> -- Crash in 
        WebCore::DragData::containsCompatibleContent due to early release 
        of types array



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20858 268f45cc-cd09-0410-ab3c-d52691b4dbfc