[Blob] Blob paging to disk patch.

storage/browser/blob/blob_data_item.h

 // Copyright (c) 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_BLOB_DATA_ITEM_H_
 #define STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_
 
 #include <ostream>
 #include <string>
 
@@ skipping 44 matching lines @@
   const DataElement* data_element_ptr() const { return item_.get(); }
   DataElement* data_element_ptr() { return item_.get(); }
 
   disk_cache::Entry* disk_cache_entry() const { return disk_cache_entry_; }
   int disk_cache_stream_index() const { return disk_cache_stream_index_; }
 
  private:
   friend class BlobDataBuilder;
   friend class BlobStorageContext;
   friend class base::RefCounted<BlobDataItem>;
+  friend class BlobMemoryController;
   friend STORAGE_EXPORT void PrintTo(const BlobDataItem& x, ::std::ostream* os);
 
   explicit BlobDataItem(scoped_ptr<DataElement> item);
   BlobDataItem(scoped_ptr<DataElement> item,
                const scoped_refptr<DataHandle>& data_handle);
   BlobDataItem(scoped_ptr<DataElement> item,
                const scoped_refptr<DataHandle>& data_handle,
                disk_cache::Entry* entry,
                int disk_cache_stream_index_);
   virtual ~BlobDataItem();
 
   scoped_ptr<DataElement> item_;
   scoped_refptr<DataHandle> data_handle_;
 
   // This naked pointer is safe because the scope is protected by the DataHandle
   // instance for disk cache entries during the lifetime of this BlobDataItem.
   disk_cache::Entry* disk_cache_entry_;
   int disk_cache_stream_index_;  // For TYPE_DISK_CACHE_ENTRY.
+
+  // This is a temporary file from the Blob system, and we need to call
+  // DecrementTempFileRefCount on the BlobMemoryController when this item
+  // is destructed.
+  bool temp_file_;
 };
 
 STORAGE_EXPORT bool operator==(const BlobDataItem& a, const BlobDataItem& b);
 STORAGE_EXPORT bool operator!=(const BlobDataItem& a, const BlobDataItem& b);
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_