Revert of Use ChromeBrowserStateManager instead of BrowserListIOS.

ios/chrome/browser/tabs/tab_model_list.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_model_list.h"
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/supports_user_data.h"
-#include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
-#include "ios/chrome/browser/browser_state/chrome_browser_state_manager.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 // Wrapper around a NSMutableArray<TabModel> allowing to bind it to a
 // base::SupportsUserData. Any base::SupportsUserData that owns this
 // wrapper will owns the reference to the TabModels.
@@ skipping 57 matching lines @@
   DCHECK([tab_models containsObject:tab_model]);
   [tab_models removeObject:tab_model];
 }
 
 NSArray<TabModel*>* GetTabModelsForChromeBrowserState(
     ios::ChromeBrowserState* browser_state) {
   TabModelList* tab_model_list =
       TabModelList::GetForBrowserState(browser_state, false);
   return tab_model_list ? [tab_model_list->tab_models() allObjects] : nil;
 }
-
-TabModel* GetLastActiveTabModelForChromeBrowserState(
-    ios::ChromeBrowserState* browser_state) {
-  TabModelList* tab_model_list =
-      TabModelList::GetForBrowserState(browser_state, false);
-  if (!tab_model_list || [tab_model_list->tab_models() count] == 0u)
-    return nil;
-
-  // There is currently no way to mark a TabModel as active. Assert that there
-  // is only one TabModel associated with |browser_state| until it is possible
-  // to mark a TabModel as active.
-  DCHECK_EQ([tab_model_list->tab_models() count], 1u);
-  return [tab_model_list->tab_models() anyObject];
-}
-
-bool IsOffTheRecordSessionActive() {
-  std::vector<ios::ChromeBrowserState*> browser_states =
-      GetApplicationContext()
-          ->GetChromeBrowserStateManager()
-          ->GetLoadedBrowserStates();
-
-  for (ios::ChromeBrowserState* browser_state : browser_states) {
-    DCHECK(!browser_state->IsOffTheRecord());
-    if (!browser_state->HasOffTheRecordChromeBrowserState())
-      continue;
-
-    ios::ChromeBrowserState* otr_browser_state =
-        browser_state->GetOffTheRecordChromeBrowserState();
-
-    TabModelList* tab_model_list =
-        TabModelList::GetForBrowserState(otr_browser_state, false);
-    if (!tab_model_list)
-      continue;
-
-    for (TabModel* tab_model in tab_model_list->tab_models()) {
-      if (![tab_model isEmpty])
-        return true;
-    }
-  }
-
-  return false;
-}