Update AX role mapping for summary to AXButton on Mac

ui/accessibility/platform/ax_platform_node_mac.mm

 // Copyright 2014 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.
 
 #import "ui/accessibility/platform/ax_platform_node_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 48 matching lines @@
       {ui::AX_ROLE_CONTENT_INFO, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DATE, @"AXDateField"},
       {ui::AX_ROLE_DATE_TIME, @"AXDateField"},
       {ui::AX_ROLE_DEFINITION, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DESCRIPTION_LIST_DETAIL, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DESCRIPTION_LIST, NSAccessibilityListRole},
       {ui::AX_ROLE_DESCRIPTION_LIST_TERM, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DIALOG, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DETAILS, NSAccessibilityGroupRole},
       {ui::AX_ROLE_DIRECTORY, NSAccessibilityListRole},
-      {ui::AX_ROLE_DISCLOSURE_TRIANGLE, NSAccessibilityDisclosureTriangleRole},
+      // If Mac supports AXExpandedChanged event with
+      // NSAccessibilityDisclosureTriangleRole, We should update
+      // AX_ROLE_DISCLOSURE_TRIANGLE mapping to
+      // NSAccessibilityDisclosureTriangleRole. http://crbug.com/558324
+      {ui::AX_ROLE_DISCLOSURE_TRIANGLE, NSAccessibilityButtonRole},
       {ui::AX_ROLE_DOCUMENT, NSAccessibilityGroupRole},
       {ui::AX_ROLE_EMBEDDED_OBJECT, NSAccessibilityGroupRole},
       {ui::AX_ROLE_FIGCAPTION, NSAccessibilityGroupRole},
       {ui::AX_ROLE_FIGURE, NSAccessibilityGroupRole},
       {ui::AX_ROLE_FOOTER, NSAccessibilityGroupRole},
       {ui::AX_ROLE_FORM, NSAccessibilityGroupRole},
       {ui::AX_ROLE_GENERIC_CONTAINER, NSAccessibilityGroupRole},
       {ui::AX_ROLE_GRID, NSAccessibilityGridRole},
       {ui::AX_ROLE_GROUP, NSAccessibilityGroupRole},
       {ui::AX_ROLE_HEADING, @"AXHeading"},
@@ skipping 423 matching lines @@
   return [[self class] nativeRoleFromAXRole:node_->GetData().role];
 }
 
 - (NSString*)AXRoleDescription {
   switch (node_->GetData().role) {
     case ui::AX_ROLE_TAB:
       // There is no NSAccessibilityTabRole or similar (AXRadioButton is used
       // instead). Do the same as NSTabView and put "tab" in the description.
       return [l10n_util::GetNSStringWithFixup(IDS_ACCNAME_TAB_ROLE_DESCRIPTION)
           lowercaseString];
+    case ui::AX_ROLE_DISCLOSURE_TRIANGLE:
+      return [l10n_util::GetNSStringWithFixup(
+          IDS_ACCNAME_DISCLOSURE_TRIANGLE_ROLE_DESCRIPTION) lowercaseString];
     default:
       break;
   }
   return NSAccessibilityRoleDescription([self AXRole], [self AXSubrole]);
 }
 
 - (NSString*)AXSubrole {
   ui::AXRole role = node_->GetData().role;
   switch (role) {
     case ui::AX_ROLE_TEXT_FIELD:
@@ skipping 164 matching lines @@
   }
   NotifyMacEvent(native_node_, event_type);
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui