Support providers with two namespaces

components/offline_items_collection/core/offline_item.h

 // Copyright 2017 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 COMPONENTS_OFFLINE_ITEMS_COLLECTION_CORE_OFFLINE_ITEM_H_
 #define COMPONENTS_OFFLINE_ITEMS_COLLECTION_CORE_OFFLINE_ITEM_H_
 
 #include <string>
 
 #include "base/time/time.h"
@@ skipping 32 matching lines @@
 // A new feature should expose these OfflineItems via an OfflineContentProvider.
 struct OfflineItem {
   OfflineItem();
   OfflineItem(const OfflineItem& other);
   explicit OfflineItem(const ContentId& id);
 
   ~OfflineItem();
 
   bool operator==(const OfflineItem& offline_item) const;
 
+  bool operator<(const OfflineItem& offline_item) const;
+
   // The id of this OfflineItem.  Used to identify this item across all relevant
   // systems.
   ContentId id;
 
   // Display Metadata.
   // ---------------------------------------------------------------------------
   // The title of the OfflineItem to display in the UI.
   std::string title;
 
   // The description of the OfflineItem to display in the UI (may or may not be
@@ skipping 52 matching lines @@
 
   // The estimated time remaining for the download in milliseconds.  -1
   // represents an unknown time remaining.  This field is not used if |state| is
   // COMPLETE.
   int64_t time_remaining_ms;
 };
 
 }  // namespace offline_items_collection
 
 #endif  // COMPONENTS_OFFLINE_ITEMS_COLLECTION_OFFLINE_ITEM_H_