Revert "Remove OwnPtr from Blink."

third_party/WebKit/Source/wtf/HashTraits.h

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2012 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
@@ skipping 137 matching lines @@
 template <typename T> struct SimpleClassHashTraits : GenericHashTraits<T> {
     static const bool emptyValueIsZero = true;
     template <typename U = void>
     struct NeedsToForbidGCOnMove {
         static const bool value = false;
     };
     static void constructDeletedValue(T& slot, bool) { new (NotNull, &slot) T(HashTableDeletedValue); }
     static bool isDeletedValue(const T& value) { return value.isHashTableDeletedValue(); }
 };
 
+template <typename P> struct HashTraits<OwnPtr<P>> : SimpleClassHashTraits<OwnPtr<P>> {
+    typedef std::nullptr_t EmptyValueType;
+
+    static EmptyValueType emptyValue() { return nullptr; }
+
+    static const bool hasIsEmptyValueFunction = true;
+    static bool isEmptyValue(const OwnPtr<P>& value) { return !value; }
+
+    typedef typename OwnPtr<P>::PtrType PeekInType;
+
+    static void store(PassOwnPtr<P> value, OwnPtr<P>& storage) { storage = std::move(value); }
+
+    typedef typename OwnPtr<P>::PtrType PeekOutType;
+    static PeekOutType peek(const OwnPtr<P>& value) { return value.get(); }
+    static PeekOutType peek(std::nullptr_t) { return 0; }
+};
+
 template <typename P> struct HashTraits<RefPtr<P>> : SimpleClassHashTraits<RefPtr<P>> {
     typedef std::nullptr_t EmptyValueType;
     static EmptyValueType emptyValue() { return nullptr; }
 
     static const bool hasIsEmptyValueFunction = true;
     static bool isEmptyValue(const RefPtr<P>& value) { return !value; }
 
     typedef RefPtrValuePeeker<P> PeekInType;
     typedef RefPtr<P>* IteratorGetType;
     typedef const RefPtr<P>* IteratorConstGetType;
@@ skipping 164 matching lines @@
 struct TraceInCollectionTrait;
 
 } // namespace WTF
 
 using WTF::HashTraits;
 using WTF::PairHashTraits;
 using WTF::NullableHashTraits;
 using WTF::SimpleClassHashTraits;
 
 #endif // WTF_HashTraits_h