Revert of Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/chrome/browser/crash_report/crash_restore_helper.mm

 // Copyright 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.
 
 #import "ios/chrome/browser/crash_report/crash_restore_helper.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/metrics/histogram_macros.h"
@@ skipping 270 matching lines @@
 
   // If the infobar is dismissed without restoring the tabs (either by closing
   // it with the cross or after a navigation), all the entries will be added to
   // the recently closed tabs.
   _sessionRestored = YES;
 
   SessionWindowIOS* window = [[SessionServiceIOS sharedService]
       loadWindowFromPath:[self sessionBackupPath]
          forBrowserState:[_tabModel browserState]];
   DCHECK(window);
-  NSArray* sessions = window.sessions;
-  if (!sessions.count)
+  if (!window.unclaimedSessions)
     return;
   sessions::TabRestoreService* const tabRestoreService =
       IOSChromeTabRestoreServiceFactory::GetForBrowserState(_browserState);
   tabRestoreService->LoadTabsFromLastSession();
 
-  web::WebState::CreateParams params(_browserState);
-  for (CRWNavigationManagerStorage* session in sessions) {
-    std::unique_ptr<web::WebState> webState =
-        web::WebState::Create(params, session);
+  while (window.unclaimedSessions) {
     // Add all tabs at the 0 position as the position is relative to an old
     // tabModel.
+    std::unique_ptr<web::WebStateImpl> webState = [window nextSession];
     tabRestoreService->CreateHistoricalTab(
         sessions::IOSLiveTab::GetForWebState(webState.get()), 0);
   }
   return;
 }
 
 @end