Use ContainerNode::hasChildren() instead of firstChild() in conditionals

Source/core/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 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 731 matching lines @@
     // previous checks, so this should remain as one of the last.
     //
     // These checks are simplified in the interest of execution speed;
     // for example, any element having an alt attribute will make it
     // not ignored, rather than just images.
     if (!getAttribute(aria_helpAttr).isEmpty() || !getAttribute(aria_describedbyAttr).isEmpty() || !getAttribute(altAttr).isEmpty() || !getAttribute(titleAttr).isEmpty())
         return false;
 
     // Don't ignore generic focusable elements like <div tabindex=0>
     // unless they're completely empty, with no children.
-    if (isGenericFocusableElement() && node->firstChild())
+    if (isGenericFocusableElement() && node->hasChildren())
         return false;
 
     if (!ariaAccessibilityDescription().isEmpty())
         return false;
 
     // By default, objects should be ignored so that the AX hierarchy is not
     // filled with unnecessary items.
     return true;
 }
 
@@ skipping 1551 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink