Clean up forward declarations in Source/core/css

Source/core/svg/SVGEnumeration.h

 /*
  * Copyright (C) 2014 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef SVGEnumeration_h
 #define SVGEnumeration_h
 
 #include "core/svg/properties/SVGProperty.h"
 
 namespace blink {
 
+class ExceptionState;
+
 class SVGEnumerationBase : public SVGPropertyBase {
 public:
     typedef std::pair<unsigned short, String> StringEntry;
     typedef Vector<StringEntry> StringEntries;
 
     // SVGEnumeration does not have a tear-off type.
     typedef void TearOffType;
     typedef unsigned short PrimitiveType;
 
     virtual ~SVGEnumerationBase();
@@ skipping 82 matching lines @@
 protected:
     explicit SVGEnumeration(Enum newValue)
         : SVGEnumerationBase(newValue, getStaticStringEntries<Enum>(), getMaxExposedEnumValue<Enum>())
     {
     }
 };
 
 } // namespace blink
 
 #endif // SVGEnumeration_h