Add more oilpan collections support

Source/wtf/DefaultAllocator.h

Index: Source/wtf/DefaultAllocator.h
diff --git a/Source/wtf/DefaultAllocator.h b/Source/wtf/DefaultAllocator.h
index 004587dec1577b4496b1de2e17f5c1361f077275..67071e06850334e00dd492fea8762698103b70d7 100644
--- a/Source/wtf/DefaultAllocator.h
+++ b/Source/wtf/DefaultAllocator.h
@@ -107,10 +107,21 @@ public:
     }
 
     template<typename T, typename Traits>
-    static void mark(...)
+    static void trace(...)
     {
         ASSERT_NOT_REACHED();
     }
+
+    template<typename T>
+    struct OtherType {
+        typedef T* Type;
+    };
+
+    template<typename T>
+    static T& getOther(T* other)
+    {
+        return *other;
+    }
 };
 
 // The Windows compiler seems to be very eager to instantiate things it won't