Add more missing closing namespace comments.

third_party/WebKit/Source/core/css/CSSFunctionValue.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/CSSFunctionValue.h"
 
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 String CSSFunctionValue::customCSSText() const
 {
     StringBuilder result;
     result.append(getValueName(m_valueID));
     result.append('(');
     result.append(CSSValueList::customCSSText());
     result.append(')');
     return result.toString();
 }
 
-}
+} // namespace blink