Move CrossThreadCopier from platform/ to wtf/

third_party/WebKit/Source/wtf/RefPtr.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2013 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.
  *
  */
 
 // RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html
 
 #ifndef WTF_RefPtr_h
 #define WTF_RefPtr_h
 
 #include "wtf/Allocator.h"
+#include "wtf/CrossThreadCopier.h"
 #include "wtf/HashTableDeletedValueType.h"
 #include "wtf/PassRefPtr.h"
+#include "wtf/ThreadSafeRefCounted.h"
+#include "wtf/TypeTraits.h"
 #include <algorithm>
 #include <utility>
 
+class SkRefCnt;
+
 namespace WTF {
 
 template <typename T> class PassRefPtr;
 template <typename T> class RefPtrValuePeeker;
 
 template <typename T> class RefPtr {
     USING_FAST_MALLOC(RefPtr);
 public:
     ALWAYS_INLINE RefPtr() : m_ptr(nullptr) {}
     ALWAYS_INLINE RefPtr(std::nullptr_t) : m_ptr(nullptr) {}
@@ skipping 37 matching lines @@
 
     void swap(RefPtr&);
 
     static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
 
 private:
     T* m_ptr;
 };
 
 template <typename T>
+struct CrossThreadCopier<RefPtr<T>> : public CrossThreadCopierPassThrough<RefPtr<T>> {
+    STATIC_ONLY(CrossThreadCopier);
+    static_assert(IsSubclassOfTemplate<T, ThreadSafeRefCounted>::value || std::is_base_of<SkRefCnt, T>::value, "RefPtr<T> can be passed across threads only if T is ThreadSafeRefCounted or SkRefCnt.");
+};
+
+template <typename T>
 template <typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
     : m_ptr(o.leakRef())
 {
 }
 
 template <typename T> inline void RefPtr<T>::clear()
 {
     T* ptr = m_ptr;
     m_ptr = nullptr;
     derefIfNotNull(ptr);
@@ skipping 89 matching lines @@
 private:
     T* m_ptr;
 };
 
 } // namespace WTF
 
 using WTF::RefPtr;
 using WTF::static_pointer_cast;
 
 #endif // WTF_RefPtr_h