Revert of Move most of the [Pass]RefPtr's of CSSPrimitiveValue to our transition types.

Source/wtf/RawPtr.h

 /*
  * Copyright (C) 2014 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 37 matching lines @@
 
     template<typename U>
     explicit RawPtr(const RawPtr<U>& other)
         : m_ptr(other.get())
     {
     }
 
     T* get() const { return m_ptr; }
     void clear() { m_ptr = 0; }
     // FIXME: oilpan: Remove release and leakRef once we remove RefPtrWillBeRawPtr.
-    RawPtr<T> release()
-    {
-        RawPtr<T> tmp = m_ptr;
-        m_ptr = 0;
-        return tmp;
-    }
+    RawPtr<T> release() const { return m_ptr; }
     T* leakRef()
     {
         T* ptr = m_ptr;
         m_ptr = 0;
         return ptr;
     }
 
     RawPtr& operator=(T* ptr)
     {
         m_ptr = ptr;
         return *this;
     }
 
     operator T*() const { return m_ptr; }
     T& operator*() const { return *m_ptr; }
     T* operator->() const { return m_ptr; }
 
 private:
     T* m_ptr;
 };
 
 } // namespace WTF
 
 using WTF::RawPtr;
 
 #endif