Made CSSPrimitiveValue::getString() only work for String types

Source/web/WebAXObject.cpp

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1221 matching lines @@
         document->updateLayoutTreeIfNeeded();
 
     Node* node = m_private->node();
     if (!node)
         return WebString();
 
     const ComputedStyle* computedStyle = node->ensureComputedStyle();
     if (!computedStyle)
         return WebString();
 
-    return WebString(CSSPrimitiveValue::create(computedStyle->display())->getStringValue());
+    return WebString(CSSPrimitiveValue::create(computedStyle->display())->cssText());
 }
 
 bool WebAXObject::accessibilityIsIgnored() const
 {
     if (isDetached())
         return false;
 
     return m_private->accessibilityIsIgnored();
 }
 
@@ skipping 360 matching lines @@
     m_private = object;
     return *this;
 }
 
 WebAXObject::operator PassRefPtrWillBeRawPtr<AXObject>() const
 {
     return m_private.get();
 }
 
 } // namespace blink