[Sync] Introduce SyncedSessionWindow type.

chrome/browser/ui/webui/foreign_session_handler.cc

 // Copyright (c) 2012 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 "chrome/browser/ui/webui/foreign_session_handler.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 283 matching lines @@
       if (is_collapsed)
         current_collapsed_sessions->SetBoolean(session_tag, true);
 
       std::unique_ptr<base::ListValue> window_list(new base::ListValue());
       const std::string group_name =
           base::FieldTrialList::FindFullName("TabSyncByRecency");
       if (group_name != "Enabled") {
         // Order tabs by visual order within window.
         for (const auto& window_pair : session->windows) {
           std::unique_ptr<base::DictionaryValue> window_data(
-              SessionWindowToValue(*window_pair.second.get()));
+              SessionWindowToValue(window_pair.second->wrapped_window));
           if (window_data.get())
             window_list->Append(std::move(window_data));
         }
       } else {
         // Order tabs by recency. This involves creating a synthetic singleton
         // window that contains all the tabs of the session.
         base::Time modification_time;
         std::vector<const ::sessions::SessionTab*> tabs;
         open_tabs->GetForeignSessionTabs(session_tag, &tabs);
         std::unique_ptr<base::ListValue> tab_values(new base::ListValue());
@@ skipping 112 matching lines @@
   // collapsed state persists.
   PrefService* prefs = Profile::FromWebUI(web_ui())->GetPrefs();
   DictionaryPrefUpdate update(prefs, prefs::kNtpCollapsedForeignSessions);
   if (is_collapsed)
     update.Get()->SetBoolean(session_tag, true);
   else
     update.Get()->Remove(session_tag, NULL);
 }
 
 }  // namespace browser_sync