[ios] WebStateList owns all WebState it manages.

ios/chrome/browser/tabs/tab_helper_util.mm

 // 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.
 
 #import "ios/chrome/browser/tabs/tab_helper_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
@@ skipping 11 matching lines @@
 #import "ios/chrome/browser/infobars/infobar_manager_impl.h"
 #include "ios/chrome/browser/reading_list/reading_list_model_factory.h"
 #import "ios/chrome/browser/reading_list/reading_list_web_state_observer.h"
 #import "ios/chrome/browser/sessions/ios_chrome_session_tab_helper.h"
 #import "ios/chrome/browser/signin/account_consistency_service_factory.h"
 #import "ios/chrome/browser/ssl/ios_security_state_tab_helper.h"
 #import "ios/chrome/browser/store_kit/store_kit_tab_helper.h"
 #import "ios/chrome/browser/sync/ios_chrome_synced_tab_delegate.h"
 #import "ios/chrome/browser/tabs/legacy_tab_helper.h"
 #import "ios/chrome/browser/tabs/tab.h"
+#import "ios/chrome/browser/tabs/tab_private.h"
 #import "ios/chrome/browser/translate/chrome_ios_translate_client.h"
 #import "ios/chrome/browser/web/blocked_popup_tab_helper.h"
 #import "ios/chrome/browser/web/network_activity_indicator_tab_helper.h"
 #import "ios/chrome/browser/web/repost_form_tab_helper.h"
 #import "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #import "ios/web/public/web_state/web_state.h"
 
 void AttachTabHelpers(web::WebState* web_state) {
+  LegacyTabHelper::CreateForWebState(web_state);
   Tab* tab = LegacyTabHelper::GetTabForWebState(web_state);
+  DCHECK(tab);
 
   ios::ChromeBrowserState* browser_state =
       ios::ChromeBrowserState::FromBrowserState(web_state->GetBrowserState());
 
   // IOSChromeSessionTabHelper comes first because it sets up the tab ID,
   // and other helpers may rely on that.
   IOSChromeSessionTabHelper::CreateForWebState(web_state);
 
   NetworkActivityIndicatorTabHelper::CreateForWebState(web_state, tab.tabId);
   IOSChromeSyncedTabDelegate::CreateForWebState(web_state);
@@ skipping 23 matching lines @@
           original_browser_state, ServiceAccessType::IMPLICIT_ACCESS),
       ios::HistoryServiceFactory::GetForBrowserState(
           original_browser_state, ServiceAccessType::IMPLICIT_ACCESS),
       ios::BookmarkModelFactory::GetForBrowserState(original_browser_state));
   history::WebStateTopSitesObserver::CreateForWebState(
       web_state,
       ios::TopSitesFactory::GetForBrowserState(original_browser_state).get());
 
   // Allow the embedder to attach tab helpers.
   ios::GetChromeBrowserProvider()->AttachTabHelpers(web_state, tab);
+
+  // Allow the Tab to attach tab helper like objects (all those objects should
+  // really be tab helpers and created above).
+  [tab attachTabHelpers];
 }