Unify and provide one IsGarbageCollectedType<T> implementation.

third_party/WebKit/Source/wtf/Functional.h

Index: third_party/WebKit/Source/wtf/Functional.h
diff --git a/third_party/WebKit/Source/wtf/Functional.h b/third_party/WebKit/Source/wtf/Functional.h
index de82d7dc1d98b2315fdbce6b9530e62d9b89e719..694963ae2bbf6c31b8e9394669225d86d7af404f 100644
--- a/third_party/WebKit/Source/wtf/Functional.h
+++ b/third_party/WebKit/Source/wtf/Functional.h
@@ -34,10 +34,15 @@
 #include "wtf/PtrUtil.h"
 #include "wtf/RefPtr.h"
 #include "wtf/ThreadSafeRefCounted.h"
+#include "wtf/TypeTraits.h"
 #include "wtf/WeakPtr.h"
 #include <tuple>
 #include <utility>
 
+namespace blink {
+template<typename T> class CrossThreadPersistent;
+}
+
 namespace WTF {
 
 // Functional.h provides a very simple way to bind a function pointer and arguments together into a function object
@@ -232,6 +237,31 @@ struct ParamStorageTraits<PassedWrapper<T>> {
     static T unwrap(StorageType& value) { return value.moveOut(); }
 };
 
+template<typename T, bool isGarbageCollected> struct PointerParamStorageTraits;
+
+template<typename T>
+struct PointerParamStorageTraits<T*, false> {
+    STATIC_ONLY(PointerParamStorageTraits);
+    using StorageType = T*;
+
+    static StorageType wrap(T* value) { return value; }
+    static T* unwrap(const StorageType& value) { return value; }
+};
+
+template<typename T>
+struct PointerParamStorageTraits<T*, true> {
+    STATIC_ONLY(PointerParamStorageTraits);
+    using StorageType = blink::CrossThreadPersistent<T>;
+
+    static StorageType wrap(T* value) { return value; }
+    static T* unwrap(const StorageType& value) { return value.get(); }
+};
+
+template<typename T>
+struct ParamStorageTraits<T*> : public PointerParamStorageTraits<T*, IsGarbageCollectedType<T>::value> {
+    STATIC_ONLY(ParamStorageTraits);
+};
+
 enum FunctionThreadAffinity {
     CrossThreadAffinity,
     SameThreadAffinity