Revert of Use ChromeBrowserStateManager instead of BrowserListIOS.

ios/chrome/browser/ui/browser_list_ios.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_BROWSER_LIST_IOS_H_
+#define IOS_CHROME_BROWSER_UI_BROWSER_LIST_IOS_H_
+
+#include <vector>
+
+#import "ios/chrome/browser/ui/browser_ios.h"
+
+namespace ios {
+class ChromeBrowserState;
+}
+
+// Modeled after chrome/browser/ui/browser_list.
+
+class BrowserListIOS {
+ public:
+  typedef std::vector<id<BrowserIOS>> BrowserVector;
+  typedef BrowserVector::iterator iterator;
+  typedef BrowserVector::const_iterator const_iterator;
+
+  // Note: browsers are not retained, just like desktop browser lists, their
+  // management is outside the list.
+  static void AddBrowser(id<BrowserIOS> browser);
+  static void RemoveBrowser(id<BrowserIOS> browser);
+
+  static id<BrowserIOS> GetLastActiveWithBrowserState(
+      ios::ChromeBrowserState* browser_state);
+
+  static const_iterator begin();
+  static const_iterator end();
+
+  static bool empty() { return !browsers_ || browsers_->empty(); }
+  static size_t size() { return browsers_ ? browsers_->size() : 0; }
+
+  // Returns true if at least one incognito session is active.
+  static bool IsOffTheRecordSessionActive();
+
+ private:
+  static BrowserVector* browsers_;
+
+  static void EnsureBrowsersIsValid();
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_BROWSER_LIST_IOS_H_