[BlobAsync] Moving async handling into BlobStorageContext & quota out.

storage/common/data_element.h

 // Copyright 2013 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_COMMON_DATA_ELEMENT_H_
 #define STORAGE_COMMON_DATA_ELEMENT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
 #include <ostream>
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/logging.h"
 #include "base/time/time.h"
 #include "storage/common/storage_common_export.h"
 #include "url/gurl.h"
 
 namespace storage {
 
 // Represents a base Web data element. This could be either one of
 // bytes, file or blob data.
 class STORAGE_COMMON_EXPORT DataElement {
  public:
+  static const uint64_t kUnknownSize = std::numeric_limits<uint64_t>::max();
+
   enum Type {
     TYPE_UNKNOWN = -1,
     TYPE_BYTES,
     // Only used with BlobStorageMsg_StartBuildingBlob
     TYPE_BYTES_DESCRIPTION,
     TYPE_FILE,
     TYPE_BLOB,
     TYPE_FILE_FILESYSTEM,
     TYPE_DISK_CACHE_ENTRY,
   };
@@ skipping 116 matching lines @@
 };
 
 STORAGE_COMMON_EXPORT bool operator==(const DataElement& a,
                                       const DataElement& b);
 STORAGE_COMMON_EXPORT bool operator!=(const DataElement& a,
                                       const DataElement& b);
 
 }  // namespace storage
 
 #endif  // STORAGE_COMMON_DATA_ELEMENT_H_