Switch SupportsUserData uses to use unique_ptr.

components/offline_pages/core/downloads/download_ui_adapter.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_PAGES_CORE_DOWNLOADS_DOWNLOAD_UI_ADAPTER_H_
 #define COMPONENTS_OFFLINE_PAGES_CORE_DOWNLOADS_DOWNLOAD_UI_ADAPTER_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 65 matching lines @@
    protected:
     virtual ~Observer() = default;
   };
 
   DownloadUIAdapter(OfflinePageModel* model,
                     RequestCoordinator* coordinator,
                     std::unique_ptr<Delegate> delegate);
   ~DownloadUIAdapter() override;
 
   static DownloadUIAdapter* FromOfflinePageModel(OfflinePageModel* model);
-  static void AttachToOfflinePageModel(DownloadUIAdapter* adapter,
-                                       OfflinePageModel* model);
+  static void AttachToOfflinePageModel(
+      std::unique_ptr<DownloadUIAdapter> adapter,
+      OfflinePageModel* model);
 
   // This adapter is potentially shared by UI elements, each of which adds
   // itself as an observer.
   // When the last observer is removed, cached list of items is destroyed and
   // next time the initial loading will take longer.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // Returns all UI items. The list contains references to items in the cache
   // and has to be used synchronously.
@@ skipping 98 matching lines @@
   int observers_count_;
 
   base::WeakPtrFactory<DownloadUIAdapter> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadUIAdapter);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGE_DOWNLOADS_DOWNLOAD_UI_ADAPTER_H_