Added basic accessibility to TreeView.

chrome/browser/accessibility/accessibility_extension_api_constants.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 "chrome/browser/accessibility/accessibility_extension_api_constants.h"
 
 namespace extension_accessibility_api_constants {
 
 // String keys for AccessibilityObject properties.
 const char kTypeKey[] = "type";
 const char kNameKey[] = "name";
 const char kContextKey[] = "context";
 const char kDetailsKey[] = "details";
 const char kValueKey[] = "details.value";
+const char kChildrenCountKey[] = "details.childrenCount";
 const char kPasswordKey[] = "details.isPassword";
 const char kItemCountKey[] = "details.itemCount";
+const char kItemDepthKey[] = "details.itemDepth";
 const char kItemIndexKey[] = "details.itemIndex";
+const char kItemExpandedKey[] = "details.isItemExpanded";
 const char kSelectionStartKey[] = "details.selectionStart";
 const char kSelectionEndKey[] = "details.selectionEnd";
 const char kCheckedKey[] = "details.isChecked";
 const char kHasSubmenuKey[] = "details.hasSubmenu";
 const char kMessageKey[] = "message";
 const char kStringValueKey[] = "details.stringValue";
 
 // Types of controls that can receive accessibility events.
 const char kTypeAlert[] = "alert";
 const char kTypeButton[] = "button";
 const char kTypeCheckbox[] = "checkbox";
 const char kTypeComboBox[] = "combobox";
 const char kTypeLink[] = "link";
 const char kTypeListBox[] = "listbox";
 const char kTypeMenu[] = "menu";
 const char kTypeMenuItem[] = "menuitem";
 const char kTypeRadioButton[] = "radiobutton";
 const char kTypeSlider[] = "slider";
 const char kTypeTab[] = "tab";
 const char kTypeTextBox[] = "textbox";
+const char kTypeTree[] = "tree";
+const char kTypeTreeItem[] = "treeitem";
 const char kTypeWindow[] = "window";
 
 }  // namespace extension_accessibility_api_constants