views: Rename ComboboxListener::ItemChanged to something more accurate.

ui/views/controls/combobox/combobox_listener.h

Index: ui/views/controls/combobox/combobox_listener.h
diff --git a/ui/views/controls/combobox/combobox_listener.h b/ui/views/controls/combobox/combobox_listener.h
index cd0f48aa542b1605603ce8c6e8d9b41131379aed..a81c5795f1913d0771c35adcb9b665b5d9789825 100644
--- a/ui/views/controls/combobox/combobox_listener.h
+++ b/ui/views/controls/combobox/combobox_listener.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 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.
 
@@ -10,14 +10,11 @@ namespace views {
 
 class Combobox;
 
-// An interface implemented by an object to let it know that the selected item
-// of a combobox changed.
+// An interface implemented by an object to let it know that the selected index
+// has changed.
 class ComboboxListener {
  public:
-  // This is invoked once the selected item changed.
-  virtual void ItemChanged(Combobox* combo_box,
-                           int prev_index,
-                           int new_index) = 0;
+  virtual void OnSelectedIndexChanged(Combobox* combobox) = 0;
 
  protected:
   virtual ~ComboboxListener() {}