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

Source/modules/storage/StorageNamespace.cpp

 /*
  * Copyright (C) 2009 Google 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 26 matching lines @@
 
 StorageNamespace::StorageNamespace(PassOwnPtr<WebStorageNamespace> webStorageNamespace)
     : m_webStorageNamespace(webStorageNamespace)
 {
 }
 
 StorageNamespace::~StorageNamespace()
 {
 }
 
-PassOwnPtrWillBeRawPtr<StorageArea> StorageNamespace::localStorageArea(SecurityOrigin* origin)
+StorageArea* StorageNamespace::localStorageArea(SecurityOrigin* origin)
 {
     ASSERT(isMainThread());
     static WebStorageNamespace* localStorageNamespace = nullptr;
     if (!localStorageNamespace)
         localStorageNamespace = Platform::current()->createLocalStorageNamespace();
     return StorageArea::create(adoptPtr(localStorageNamespace->createStorageArea(origin->toString())), LocalStorage);
 }
 
-PassOwnPtrWillBeRawPtr<StorageArea> StorageNamespace::storageArea(SecurityOrigin* origin)
+StorageArea* StorageNamespace::storageArea(SecurityOrigin* origin)
 {
     return StorageArea::create(adoptPtr(m_webStorageNamespace->createStorageArea(origin->toString())), SessionStorage);
 }
 
 bool StorageNamespace::isSameNamespace(const WebStorageNamespace& sessionNamespace) const
 {
     return m_webStorageNamespace && m_webStorageNamespace->isSameNamespace(sessionNamespace);
 }
 
 } // namespace blink