Remove OwnPtr from Blink.

third_party/WebKit/Source/modules/storage/StorageClient.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef StorageClient_h
 #define StorageClient_h
 
 #include "modules/storage/StorageArea.h"
-#include "wtf/PassOwnPtr.h"
+#include <memory>
 
 namespace blink {
 
 class StorageNamespace;
 
 class StorageClient {
 public:
     virtual ~StorageClient() { }
 
-    virtual PassOwnPtr<StorageNamespace> createSessionStorageNamespace() = 0;
+    virtual std::unique_ptr<StorageNamespace> createSessionStorageNamespace() = 0;
     virtual bool canAccessStorage(LocalFrame*, StorageType) const = 0;
 };
 
 } // namespace blink
 
 #endif // StorageClient_h