CSS.escape('\0') should not throw.

third_party/WebKit/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 12 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * 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 "core/css/DOMWindowCSS.h"
 
-#include "bindings/core/v8/ExceptionState.h"
 #include "core/css/CSSMarkup.h"
 #include "core/css/CSSPropertyMetadata.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/parser/CSSParser.h"
-#include "core/dom/ExceptionCode.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 bool DOMWindowCSS::supports(const String& property, const String& value)
 {
     CSSPropertyID unresolvedProperty = unresolvedCSSPropertyID(property);
     if (unresolvedProperty == CSSPropertyInvalid)
         return false;
     ASSERT(CSSPropertyMetadata::isEnabledProperty(unresolvedProperty));
 
     // This will return false when !important is present
     RefPtrWillBeRawPtr<MutableStylePropertySet> dummyStyle = MutableStylePropertySet::create(HTMLStandardMode);
     return CSSParser::parseValue(dummyStyle.get(), unresolvedProperty, value, false, 0);
 }
 
 bool DOMWindowCSS::supports(const String& conditionText)
 {
     return CSSParser::parseSupportsCondition(conditionText);
 }
 
-String DOMWindowCSS::escape(const String& ident, ExceptionState& exceptionState)
+String DOMWindowCSS::escape(const String& ident)
 {
     StringBuilder builder;
-    if (!serializeIdentifier(ident, builder)) {
-        exceptionState.throwDOMException(InvalidCharacterError, "The string contains an invalid character.");
-        return String();
-    }
+    serializeIdentifier(ident, builder);
     return builder.toString();
 }
 
 }