Multi-tab: Adding new Notification when tab selection changes.

chrome/browser/tabs/tab_strip_selection_model.h

 // Copyright (c) 2011 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 CHROME_BROWSER_TABS_TAB_STRIP_SELECTION_MODEL_H_
 #define CHROME_BROWSER_TABS_TAB_STRIP_SELECTION_MODEL_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 77 matching lines @@
   // selected indices.
   void Clear();
 
   // Returns the selected indices. The selection is always ordered in acending
   // order.
   const SelectedIndices& selected_indices() const { return selected_indices_; }
 
   // Copies the selection from |source| to this.
   void Copy(const TabStripSelectionModel& source);
 
+  // Compares this selection with |rhs|.
+  bool Equals(const TabStripSelectionModel& rhs) const;
+
  private:
   SelectedIndices selected_indices_;
 
   int active_;
 
   int anchor_;
 
   DISALLOW_COPY_AND_ASSIGN(TabStripSelectionModel);
 };
 
 #endif  // CHROME_BROWSER_TABS_TAB_STRIP_SELECTION_MODEL_H_