[Storage] Blob items are now shared between blobs. Ready for disk swap.

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 "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "storage/browser/blob/shareable_file_reference.h"
 #include "storage/browser/storage_browser_export.h"
 #include "storage/common/data_element.h"
 
 namespace storage {
 class BlobDataBuilder;
 class BlobStorageContext;
 
 // Ref counted blob item.  This class owns the backing data of the blob item.
 // The backing data is immutable, and cannot change after creation.
 // The purpose of this class is to allow the resource to stick around in the
 // snapshot even after the resource was swapped in the blob (either to disk or
 // to memory) by the BlobStorageContext.
 class STORAGE_EXPORT BlobDataItem : public base::RefCounted<BlobDataItem> {
  public:
-  storage::DataElement::Type type() const { return item_->type(); }
+  DataElement::Type type() const { return item_->type(); }
   const char* bytes() const { return item_->bytes(); }
   const base::FilePath& path() const { return item_->path(); }
   const GURL& filesystem_url() const { return item_->filesystem_url(); }
   const std::string& blob_uuid() const { return item_->blob_uuid(); }
   uint64 offset() const { return item_->offset(); }
   uint64 length() const { return item_->length(); }
   const base::Time& expected_modification_time() const {
     return item_->expected_modification_time();
   }
   const DataElement& data_element() const { return *item_; }
   const DataElement* data_element_ptr() const { return item_.get(); }
 
  private:
   friend class BlobDataBuilder;
   friend class BlobStorageContext;
   friend class base::RefCounted<BlobDataItem>;
+
   BlobDataItem(scoped_ptr<DataElement> item);
   BlobDataItem(scoped_ptr<DataElement> item,
                scoped_refptr<ShareableFileReference> file_handle);
   virtual ~BlobDataItem();
 
-  scoped_ptr<storage::DataElement> item_;
+  scoped_ptr<DataElement> item_;
   scoped_refptr<ShareableFileReference> file_handle_;
 };
 
 #if defined(UNIT_TEST)
 inline bool operator==(const BlobDataItem& a, const BlobDataItem& b) {
   return a.data_element() == b.data_element();
 }
 
 inline bool operator!=(const BlobDataItem& a, const BlobDataItem& b) {
   return !(a == b);
 }
 #endif  // defined(UNIT_TEST)
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_DATA_ITEM_H_