Add support for disabling CSS Properties at runtime

Source/core/css/DOMWindowCSS.cpp

 /*
  * Copyright (C) 2012 Motorola Mobility 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
@@ skipping 13 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "DOMWindowCSS.h"
 
 #include "CSSParser.h"
+#include "core/page/RuntimeCSSEnabled.h"
 #include "StylePropertySet.h"
 #include <wtf/text/WTFString.h>
 
 namespace WebCore {
 
 PassRefPtr<DOMWindowCSS> DOMWindowCSS::create()
 {
     return adoptRef(new DOMWindowCSS());
 }
 
 static String valueWithoutImportant(const String& value)
 {
     if (!value.endsWith("important", false))
         return value;
 
     String newValue = value;
     int bangIndex = newValue.length() - 9 - 1;
     if (newValue[bangIndex] == ' ')
         bangIndex--;
     newValue = newValue.left(bangIndex);
 
     return newValue;
 }
 
 bool DOMWindowCSS::supports(const String& property, const String& value) const
 {
     CSSPropertyID propertyID = cssPropertyID(property.stripWhiteSpace());
+    if (propertyID == CSSPropertyInvalid)
+        return false;
 
-    if (propertyID == CSSPropertyInvalid)
+    if (!RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID))
         return false;
 
     // CSSParser::parseValue() won't work correctly if !important is present,
     // so just get rid of it. It doesn't matter to supports() if it's actually
     // there or not, provided how it's specified in the value is correct.
     String normalizedValue = value.stripWhiteSpace().simplifyWhiteSpace();
     normalizedValue = valueWithoutImportant(normalizedValue);
 
     if (normalizedValue.isEmpty())
         return false;
 
     RefPtr<StylePropertySet> dummyStyle = StylePropertySet::create();
     return CSSParser::parseValue(dummyStyle.get(), propertyID, normalizedValue, false, CSSStrictMode, 0);
 }
 
 bool DOMWindowCSS::supports(const String& conditionText) const
 {
     CSSParserContext context(CSSStrictMode);
     CSSParser parser(context);
     return parser.parseSupportsCondition(conditionText);
 }
 
 }