Switch SupportsUserData uses to use unique_ptr.

components/offline_pages/core/downloads/download_ui_adapter.cc

 // 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.
 
 #include "components/offline_pages/core/downloads/download_ui_adapter.h"
 
 #include "base/bind.h"
 #include "base/guid.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 14 matching lines @@
 
 // static
 DownloadUIAdapter* DownloadUIAdapter::FromOfflinePageModel(
     OfflinePageModel* model) {
   DCHECK(model);
   return static_cast<DownloadUIAdapter*>(
       model->GetUserData(kDownloadUIAdapterKey));
 }
 
 // static
-void DownloadUIAdapter::AttachToOfflinePageModel(DownloadUIAdapter* adapter,
-                                                 OfflinePageModel* model) {
+void DownloadUIAdapter::AttachToOfflinePageModel(
+    std::unique_ptr<DownloadUIAdapter> adapter,
+    OfflinePageModel* model) {
   DCHECK(adapter);
   DCHECK(model);
-  model->SetUserData(kDownloadUIAdapterKey, adapter);
+  model->SetUserData(kDownloadUIAdapterKey, std::move(adapter));
 }
 
 DownloadUIAdapter::ItemInfo::ItemInfo(const OfflinePageItem& page,
                                       bool temporarily_hidden)
     : ui_item(base::MakeUnique<DownloadUIItem>(page)),
       is_request(false),
       offline_id(page.offline_id),
       client_id(page.client_id),
       temporarily_hidden(temporarily_hidden) {}
 
@@ skipping 313 matching lines @@
 
   if (!deleting_item_->temporarily_hidden && state_ == State::LOADED) {
     for (Observer& observer : observers_)
       observer.ItemDeleted(guid);
   }
 
   deleting_item_.reset();
 }
 
 }  // namespace offline_pages