Simplify DOMTokenList::validateToken() code

Source/core/dom/DOMTokenList.cpp

 /*
  * Copyright (C) 2010 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:
  * 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
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 
 namespace blink {
 
 bool DOMTokenList::validateToken(const String& token, ExceptionState& exceptionState)
 {
     if (token.isEmpty()) {
         exceptionState.throwDOMException(SyntaxError, "The token provided must not be empty.");
         return false;
     }
 
-    unsigned length = token.length();
-    for (unsigned i = 0; i < length; ++i) {
-        if (isHTMLSpace<UChar>(token[i])) {
-            exceptionState.throwDOMException(InvalidCharacterError, "The token provided ('" + token + "') contains HTML space characters, which are not valid in tokens.");
-            return false;
-        }
+    if (token.find(isHTMLSpace) != kNotFound) {
+        exceptionState.throwDOMException(InvalidCharacterError, "The token provided ('" + token + "') contains HTML space characters, which are not valid in tokens.");
+        return false;
     }
 
     return true;
 }
 
 bool DOMTokenList::validateTokens(const Vector<String>& tokens, ExceptionState& exceptionState)
 {
     for (size_t i = 0; i < tokens.size(); ++i) {
         if (!validateToken(tokens[i], exceptionState))
             return false;
@@ skipping 185 matching lines @@
                 output.append(' ');
         } else {
             output.append(token); // Step 9
         }
     }
 
     return output.toAtomicString();
 }
 
 } // namespace blink