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

ui/views/controls/combobox/combobox.cc

 // 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.
 
 #include "ui/views/controls/combobox/combobox.h"
 
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/keycodes/keyboard_codes.h"
@@ skipping 36 matching lines @@
   PreferredSizeChanged();
 }
 
 void Combobox::SetSelectedIndex(int index) {
   selected_index_ = index;
   if (native_wrapper_)
     native_wrapper_->UpdateSelectedIndex();
 }
 
 void Combobox::SelectionChanged() {
-  int prev_selected_index = selected_index_;
   selected_index_ = native_wrapper_->GetSelectedIndex();
   if (listener_)
-    listener_->ItemChanged(this, prev_selected_index, selected_index_);
+    listener_->OnSelectedIndexChanged(this);
   if (GetWidget()) {
     GetWidget()->NotifyAccessibilityEvent(
         this, ui::AccessibilityTypes::EVENT_VALUE_CHANGED, false);
   }
 }
 
 void Combobox::SetAccessibleName(const string16& name) {
   accessible_name_ = name;
 }
 
@@ skipping 77 matching lines @@
     native_wrapper_->UpdateSelectedIndex();
     native_wrapper_->UpdateEnabled();
   }
 }
 
 std::string Combobox::GetClassName() const {
   return kViewClassName;
 }
 
 }  // namespace views