Multi-tab: Adding new Notification when tab selection changes (again).

chrome/browser/tabs/tab_strip_selection_model.cc

 // 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.
 
 #include "chrome/browser/tabs/tab_strip_selection_model.h"
 
 #include <algorithm>
 #include <valarray>
 
 #include "base/logging.h"
@@ skipping 123 matching lines @@
   anchor_ = active_ = kUnselectedIndex;
   SelectedIndices empty_selection;
   selected_indices_.swap(empty_selection);
 }
 
 void TabStripSelectionModel::Copy(const TabStripSelectionModel& source) {
   selected_indices_ = source.selected_indices_;
   active_ = source.active_;
   anchor_ = source.anchor_;
 }
+
+bool TabStripSelectionModel::Equals(const TabStripSelectionModel& rhs) const {
+  return active_ == rhs.active() &&
+      anchor_ == rhs.anchor() &&
+      selected_indices() == rhs.selected_indices();
+}