[M60 Merge] No AX objects for comments and other irrelevant node types

third_party/WebKit/Source/modules/accessibility/AXObjectImpl.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 809 matching lines @@
   UpdateCachedAttributeValuesIfNeeded();
   return cached_has_inherited_presentational_role_;
 }
 
 bool AXObjectImpl::IsPresentationalChild() const {
   UpdateCachedAttributeValuesIfNeeded();
   return cached_is_presentational_child_;
 }
 
 bool AXObjectImpl::CanReceiveAccessibilityFocus() const {
-  const Node* node = this->GetNode();
-  if (!node)
-    return false;
-
-  const Element* elem = ToElement(node);
+  const Element* elem = GetElement();
   if (!elem)
     return false;
 
   // Focusable, and not forwarding the focus somewhere else
   if (elem->IsFocusable() && !elem->FastHasAttribute(aria_activedescendantAttr))
     return true;
 
   // aria-activedescendant focus
   return elem->FastHasAttribute(idAttr) && AncestorExposesActiveDescendant();
 }
@@ skipping 1290 matching lines @@
 }
 
 DEFINE_TRACE(AXObjectImpl) {
   visitor->Trace(children_);
   visitor->Trace(parent_);
   visitor->Trace(cached_live_region_root_);
   visitor->Trace(ax_object_cache_);
 }
 
 }  // namespace blink