Move CrossThreadCopier from platform/ to wtf/

third_party/WebKit/Source/wtf/PassRefPtr.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Library General Public License for more details.
  *
  *  You should have received a copy of the GNU Library General Public License
  *  along with this library; see the file COPYING.LIB.  If not, write to
  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  *  Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef WTF_PassRefPtr_h
 #define WTF_PassRefPtr_h
 
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
+#include "wtf/CrossThreadCopier.h"
+#include "wtf/ThreadSafeRefCounted.h"
 #include "wtf/TypeTraits.h"
 
+class SkRefCnt;
+
 namespace WTF {
 
 template <typename T> class RefPtr;
 template <typename T> class PassRefPtr;
 template <typename T> PassRefPtr<T> adoptRef(T*);
 
 inline void adopted(const void*) {}
 
 // requireAdoption() is not overloaded for WTF::RefCounted, which has a built-in
 // assumption that adoption is required. requireAdoption() is for bootstrapping
@@ skipping 55 matching lines @@
     PassRefPtr& operator=(const PassRefPtr&)
     {
         static_assert(!sizeof(T*), "PassRefPtr should never be assigned to");
         return *this;
     }
 
     mutable T* m_ptr;
 };
 
 template <typename T>
+struct CrossThreadCopier<PassRefPtr<T>> : public CrossThreadCopierPassThrough<PassRefPtr<T>> {
+    STATIC_ONLY(CrossThreadCopier);
+    static_assert(IsSubclassOfTemplate<T, ThreadSafeRefCounted>::value || std::is_base_of<SkRefCnt, T>::value, "PassRefPtr<T> can be passed across threads only if T is ThreadSafeRefCounted or SkRefCnt.");
+};
+
+template <typename T>
 PassRefPtr<T> wrapPassRefPtr(T* ptr)
 {
     return PassRefPtr<T>(ptr);
 }
 
 template <typename T>
 template <typename U> inline PassRefPtr<T>::PassRefPtr(const RefPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
     : m_ptr(o.get())
 {
     T* ptr = m_ptr;
@@ skipping 99 matching lines @@
     return p.get();
 }
 
 } // namespace WTF
 
 using WTF::PassRefPtr;
 using WTF::adoptRef;
 using WTF::static_pointer_cast;
 
 #endif // WTF_PassRefPtr_h