Do the early return when role is different than UnknownRole

Source/modules/accessibility/AXTableRow.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 38 matching lines @@
 PassRefPtr<AXTableRow> AXTableRow::create(RenderObject* renderer)
 {
     return adoptRef(new AXTableRow(renderer));
 }
 
 AccessibilityRole AXTableRow::determineAccessibilityRole()
 {
     if (!isTableRow())
         return AXRenderObject::determineAccessibilityRole();
 
-    m_ariaRole = determineAriaRoleAttribute();
-
-    AccessibilityRole ariaRole = ariaRoleAttribute();
-    if (ariaRole != UnknownRole)
-        return ariaRole;
+    if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
+        return m_ariaRole;
 
     return RowRole;
 }
 
 bool AXTableRow::isTableRow() const
 {
     AXObject* table = parentTable();
     if (!table || !table->isAXTable())
         return false;
 
@@ skipping 48 matching lines @@
         return 0;
 
     Node* cellNode = cellRenderer->node();
     if (!cellNode || !cellNode->hasTagName(thTag))
         return 0;
 
     return cell;
 }
 
 } // namespace blink