Fix build due to double declaration of TraceTrait<RefPtr<T> >

Source/heap/Handle.h

Index: Source/heap/Handle.h
diff --git a/Source/heap/Handle.h b/Source/heap/Handle.h
index 4e30fdf9b3cdc29f5414aedbf7eca7d634a3836e..4ce9bb218db7a06b2f159420977152f20419f5f2 100644
--- a/Source/heap/Handle.h
+++ b/Source/heap/Handle.h
@@ -396,17 +396,6 @@ public:
     }
 };
 
-// TraceTrait to allow compilation of trace method bodies when oilpan is disabled.
-// This should never be called, but is needed to compile.
-template<typename T>
-class TraceTrait<RefPtr<T> > {
-public:
-    static void trace(Visitor*, void*)
-    {
-        ASSERT_NOT_REACHED();
-    }
-};
-
 // WeakMember is similar to Member in that it is used to point to other oilpan
 // heap allocated objects.
 // However instead of creating a strong pointer to the object, the WeakMember creates