Translate: New Bubble UX (for the view toolkit)

chrome/browser/ui/translate/language_combobox_model.cc

 // Copyright 2013 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/ui/translate/language_combobox_model.h"
 
 #include "chrome/browser/ui/translate/translate_bubble_model.h"
 
 LanguageComboboxModel::LanguageComboboxModel(
     int default_index,
     TranslateBubbleModel* model)
-    : default_index_(default_index),
+    : default_index_(default_index < 0 ? 0 : default_index),
       model_(model) {
+  // view::Combobox can't treate an negative index, but |default_index| can be
+  // negative when, for example, the page's language can't be detected.
 }
 
 LanguageComboboxModel::~LanguageComboboxModel() {
 }
 
 int LanguageComboboxModel::GetItemCount() const {
   return model_->GetNumberOfLanguages();
 }
 
 string16 LanguageComboboxModel::GetItemAt(int index) {
   return model_->GetLanguageNameAt(index);
 }
 
 bool LanguageComboboxModel::IsItemSeparatorAt(int index) {
   return false;
 }
 
 int LanguageComboboxModel::GetDefaultIndex() const {
   return default_index_;
 }