WebPrivatePtr: avoid creating temporary Persistent<> on assignment.

public/platform/WebPrivatePtr.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 114 matching lines @@
         m_handle = 0;
     }
 
 private:
     WebCore::Persistent<T>* m_handle;
 };
 
 template<typename T>
 class PtrStorageImpl<T, RefCountedGarbageCollectedLifetime> : public PtrStorageImpl<T, GarbageCollectedLifetime> {
 public:
-    void assign(const PassRefPtr<T>& val) { PtrStorageImpl<T, GarbageCollectedLifetime>::assign(val.get()); }
+    void assign(const PassRefPtrWillBeRawPtr<T>& val) { PtrStorageImpl<T, GarbageCollectedLifetime>::assign(val.get()); }
 
     void assign(const PtrStorageImpl& other) { PtrStorageImpl<T, GarbageCollectedLifetime>::assign(other.get()); }
 };
 
 template<typename T>
 class PtrStorage : public PtrStorageImpl<T, LifetimeOf<T>::value> {
 public:
     static PtrStorage& fromSlot(void** slot)
     {
         COMPILE_ASSERT(sizeof(PtrStorage) == sizeof(void*), PtrStorage_must_be_pointer_size);
@@ skipping 119 matching lines @@
     // Disable the copy constructor; classes that contain a WebPrivatePtr
     // should implement their copy constructor using assign().
     WebPrivatePtr(const WebPrivatePtr<T>&);
 
     void* m_storage;
 };
 
 } // namespace blink
 
 #endif