WindowFeatures arguments shoud ignore invalid characters in values

Source/core/page/WindowFeatures.cpp

 /*
  *  Copyright (C) 2000 Harri Porten (porten@kde.org)
  *  Copyright (C) 2006 Jon Shier (jshier@iastate.edu)
  *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reseved.
  *  Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
@@ skipping 56 matching lines @@
         return;
     }
 
     menuBarVisible = false;
     statusBarVisible = false;
     toolBarVisible = false;
     locationBarVisible = false;
     scrollbarsVisible = false;
 
     // Tread lightly in this code -- it was specifically designed to mimic Win IE's parsing behavior.
-    int keyBegin, keyEnd;
-    int valueBegin, valueEnd;
+    unsigned keyBegin, keyEnd;
+    unsigned valueBegin, valueEnd;
 
-    int i = 0;
-    int length = features.length();
     String buffer = features.lower();
-    while (i < length) {
+    unsigned length = buffer.length();
+    for (unsigned i = 0; i < length; ) {
         // skip to first non-separator, but don't skip past the end of the string
         while (i < length && isWindowFeaturesSeparator(buffer[i]))
             i++;
         keyBegin = i;
 
         // skip to first separator
         while (i < length && !isWindowFeaturesSeparator(buffer[i]))
             i++;
         keyEnd = i;
 
@@ skipping 168 matching lines @@
         if (separatorPosition != kNotFound) {
             value = featureString.substring(separatorPosition + 1).stripWhiteSpace().lower();
             value = value.left(value.find(' '));
         }
 
         map.set(key, value);
     }
 }
 
 } // namespace WebCore