Reviewed by Oliver Hunt.

        Custom prototypes on DOM objects don't persist after garbage collection
        https://bugs.webkit.org/show_bug.cgi?id=59412
        
        SunSpider reports no change.
        
        The hasCustomProperties() check didn't check for a custom prototype.

        * runtime/JSObject.h:
        (JSC::JSObject::hasCustomProperties): Changed to delegate to Structure
        because it is the "truth" about an object's pedigree.

        * runtime/Structure.cpp:
        (JSC::Structure::Structure):
        * runtime/Structure.h:
        (JSC::Structure::didTransition): Track whether a Structure has ever
        transitioned for any reason. If so, we have to assume that the object
        holding it is custom in some way.
2011-04-25  Geoffrey Garen  <ggaren@apple.com>

        Reviewed by Oliver Hunt.

        Custom prototypes on DOM objects don't persist after garbage collection
        https://bugs.webkit.org/show_bug.cgi?id=59412

        * fast/dom/gc-custom-prototype-expected.txt: Added.
        * fast/dom/gc-custom-prototype.html: Added.
        * fast/dom/script-tests/dataset-gc.js:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@84882 268f45cc-cd09-0410-ab3c-d52691b4dbfc