Revert of Moved NavigationManagerImpl serialization out of CRWSessionController.

ios/chrome/browser/crash_report/crash_restore_helper.mm

Index: ios/chrome/browser/crash_report/crash_restore_helper.mm
diff --git a/ios/chrome/browser/crash_report/crash_restore_helper.mm b/ios/chrome/browser/crash_report/crash_restore_helper.mm
index 6a66ab781b8249714659792f9c02f3b4311bfa65..ad2b05f963ad6bad12ca8240ae26bedf3f1a5739 100644
--- a/ios/chrome/browser/crash_report/crash_restore_helper.mm
+++ b/ios/chrome/browser/crash_report/crash_restore_helper.mm
@@ -288,19 +288,16 @@
       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);
   }