[BlobAsync] Asynchronous Blob Construction Final Patch

storage/browser/blob/shareable_blob_data_item.h

 // Copyright 2015 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 STORAGE_BROWSER_BLOB_SHAREABLE_BLOB_DATA_ITEM_H_
 #define STORAGE_BROWSER_BLOB_SHAREABLE_BLOB_DATA_ITEM_H_
 
+#include <string>
+
 #include "base/containers/hash_tables.h"
 #include "base/hash.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "storage/common/data_element.h"
 
 namespace storage {
-
 class BlobDataItem;
+class InternalBlobData;
 
 // This class allows blob items to be shared between blobs, and is only used by
 // BlobStorageContext. This class contains both the blob data item and the uuids
 // of all the blobs using this item.
 // The data in this class (the item) is immutable, but the item itself can be
 // swapped out with an item with the same data but a different backing (think
 // RAM vs file backed).
 class ShareableBlobDataItem : public base::RefCounted<ShareableBlobDataItem> {
  public:
   ShareableBlobDataItem(const std::string& blob_uuid,
                         const scoped_refptr<BlobDataItem>& item);
 
   const scoped_refptr<BlobDataItem>& item();
 
   base::hash_set<std::string>& referencing_blobs() {
     return referencing_blobs_;
   }
 
  private:
   friend class base::RefCounted<ShareableBlobDataItem>;
+  friend class InternalBlobData;
   ~ShareableBlobDataItem();
 
   scoped_refptr<BlobDataItem> item_;
 
   base::hash_set<std::string> referencing_blobs_;
 
   DISALLOW_COPY_AND_ASSIGN(ShareableBlobDataItem);
 };
 
 }  // namespace storage
 #endif  // STORAGE_BROWSER_BLOB_SHAREABLE_BLOB_DATA_ITEM_H_