Introduce InlinedGlobalMarkingVisitor

Source/wtf/TypeTraits.h

Index: Source/wtf/TypeTraits.h
diff --git a/Source/wtf/TypeTraits.h b/Source/wtf/TypeTraits.h
index 92f8cebb2b7b02d00e717be8d7902c8af2e656da..1a9f4265a79a19acf23daaa71f3208e3cc0a3459 100644
--- a/Source/wtf/TypeTraits.h
+++ b/Source/wtf/TypeTraits.h
@@ -240,6 +240,10 @@ namespace WTF {
         typedef T Type;
     };
 
+    template <typename T> struct Identity {
+        typedef T type; 
+    };
+
     template <typename T> struct RemoveConst {
         typedef T Type;
     };
@@ -303,6 +307,8 @@ namespace WTF {
 namespace blink {
 
 class JSONValue;
+class InlinedGlobalMarkingVisitor;
+class Visitor;
 
 } // namespace blink
 
@@ -318,23 +324,42 @@ namespace WTF {
     };
 
 template<typename T>
+class HasTraceNewMethod {
+    typedef char YesType;
+    typedef struct NoType {
+        char padding[8];
+    } NoType;
+#if COMPILER(MSVC)
+    QUACK!
+#else
+    template<size_t> struct HasMethod;
+    template<typename V> static YesType checkHasTraceNewMethod(HasMethod<sizeof(static_cast<void (V::*)(blink::InlinedGlobalMarkingVisitor)>(&V::trace))>*);
+#endif // COMPILER(MSVC)
+    template<typename V> static NoType checkHasTraceNewMethod(...);
+public:
+    static const bool value = sizeof(YesType) + sizeof(T) == sizeof(checkHasTraceNewMethod<T>(0)) + sizeof(T);
+};
+
+template<typename T>
 class NeedsTracing {
     typedef char YesType;
     typedef struct NoType {
         char padding[8];
     } NoType;
 #if COMPILER(MSVC)
+    QUACK!
     template<typename V> static YesType checkHasTraceMethod(char[&V::trace != 0]);
 #else
     template<size_t> struct HasMethod;
-    template<typename V> static YesType checkHasTraceMethod(HasMethod<sizeof(&V::trace)>*);
+    template<typename V> static YesType checkHasTraceMethod(HasMethod<sizeof(static_cast<void (V::*)(blink::Visitor*)>(&V::trace))>*);
 #endif // COMPILER(MSVC)
     template<typename V> static NoType checkHasTraceMethod(...);
 public:
     // We add sizeof(T) to both sides here, because we want it to fail for
     // incomplete types. Otherwise it just assumes that incomplete types do not
     // have a trace method, which may not be true.
-    static const bool value = sizeof(YesType) + sizeof(T) == sizeof(checkHasTraceMethod<T>(0)) + sizeof(T);
+    static const bool hasTraceMethod = sizeof(YesType) + sizeof(T) == sizeof(checkHasTraceMethod<T>(0)) + sizeof(T);
+    static const bool value = hasTraceMethod || HasTraceNewMethod<T>::value;
 };
 
 // Convenience template wrapping the NeedsTracingLazily template in