Oilpan: Forbid adoptRef(X*) where X is RefCountedGarbageCollected

Source/wtf/PassRefPtr.h

Index: Source/wtf/PassRefPtr.h
diff --git a/Source/wtf/PassRefPtr.h b/Source/wtf/PassRefPtr.h
index a099eef5aa35ca287fa50971a04da5e4b812829d..904d9c6bbd0821ee49bb2f06e26cf2e5072874b7 100644
--- a/Source/wtf/PassRefPtr.h
+++ b/Source/wtf/PassRefPtr.h
@@ -183,8 +183,11 @@ namespace WTF {
         return a.get() != b.get();
     }
 
+    template<typename T> class RefCountedGarbageCollected;

[haraken, 2014/10/12 15:16:45]

I'm not sure if this forward declaration is allowed (RefCountedGarbageCollected
is defined in platform/).

[sof, 2014/10/13 12:11:30]

It doesn't quite set a precedent, TypeTraits.h already brings a blink name into
scope like this.

A compile-time name "use" entirely, so it seems reasonable to allow&enable
checks such as this.

[sof, 2014/10/13 12:11:30]

Don't think there is a "using" for it (or in scope), so move the forward decl up
a bit and wrap it in "namespace blink { ... }" (and refer to it as
blink::RefCountedGarbageCollected<> below)? 

     template<typename T> PassRefPtr<T> adoptRef(T* p)
     {
+        static const bool notRefCountedGarbageCollected = !WTF::IsSubclassOfTemplate<typename WTF::RemoveConst<T>::Type, RefCountedGarbageCollected>::value;
+        COMPILE_ASSERT(notRefCountedGarbageCollected, adoptRefIsNotAllowedForRefCountedGarbageCollected);
         adopted(p);
         return PassRefPtr<T>(p, PassRefPtr<T>::AdoptRef);
     }