Oilpan: have Storage objects reside on the heap by default.

Source/modules/storage/StorageNamespace.h

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 27 matching lines @@
 namespace blink {
 
 class SecurityOrigin;
 class StorageArea;
 
 class MODULES_EXPORT StorageNamespace {
 public:
     explicit StorageNamespace(PassOwnPtr<blink::WebStorageNamespace>);
     ~StorageNamespace();
 
-    static PassOwnPtrWillBeRawPtr<StorageArea> localStorageArea(SecurityOrigin*);
+    static StorageArea* localStorageArea(SecurityOrigin*);
 
-    PassOwnPtrWillBeRawPtr<StorageArea> storageArea(SecurityOrigin*);
+    StorageArea* storageArea(SecurityOrigin*);
     bool isSameNamespace(const blink::WebStorageNamespace& sessionNamespace) const;
 
 private:
     OwnPtr<blink::WebStorageNamespace> m_webStorageNamespace;
 };
 
 } // namespace blink
 
 #endif // StorageNamespace_h