Fix WebView accessibility

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 38 matching lines @@
       {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},
       {ui::AX_ROLE_DIV, NSAccessibilityGroupRole},
       {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_GRID, NSAccessibilityGridRole},
       {ui::AX_ROLE_GROUP, NSAccessibilityGroupRole},
       {ui::AX_ROLE_HEADING, @"AXHeading"},
       {ui::AX_ROLE_IFRAME, NSAccessibilityGroupRole},
       {ui::AX_ROLE_IFRAME_PRESENTATIONAL, NSAccessibilityGroupRole},
       {ui::AX_ROLE_IGNORED, NSAccessibilityUnknownRole},
@@ skipping 268 matching lines @@
 void AXPlatformNodeMac::NotifyAccessibilityEvent(ui::AXEvent event_type) {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui