Mac a11y: Add RoleDescription and Value attributes to accessibility information.

content/browser/accessibility/browser_accessibility_cocoa.mm

 // 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 <execinfo.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
@@ skipping 1618 matching lines @@
   return CreateTextMarker(*first_text_object, 0);
 }
 
 // Returns a subrole based upon the role.
 - (NSString*) subrole {
   if (![self instanceActive])
     return nil;
   ui::AXRole browserAccessibilityRole = [self internalRole];
   if (browserAccessibilityRole == ui::AX_ROLE_TEXT_FIELD &&
       GetState(browserAccessibility_, ui::AX_STATE_PROTECTED)) {
-    return @"AXSecureTextField";
+    return NSAccessibilitySecureTextFieldSubrole;
   }
 
   if (browserAccessibilityRole == ui::AX_ROLE_DESCRIPTION_LIST)
-    return @"AXDefinitionList";
+    return NSAccessibilityDefinitionListSubrole;
 
   if (browserAccessibilityRole == ui::AX_ROLE_LIST)
-    return @"AXContentList";
+    return NSAccessibilityContentListSubrole;
 
   return [AXPlatformNodeCocoa nativeSubroleFromAXRole:browserAccessibilityRole];
 }
 
 // Returns all tabs in this subtree.
 - (NSArray*)tabs {
   if (![self instanceActive])
     return nil;
   NSMutableArray* tabSubtree = [[[NSMutableArray alloc] init] autorelease];
 
@@ skipping 956 matching lines @@
   if (![self instanceActive])
     return [super hash];
   return browserAccessibility_->GetId();
 }
 
 - (BOOL)accessibilityShouldUseUniqueId {
   return YES;
 }
 
 @end