Slim includes in CSSValue.h

third_party/WebKit/Source/core/css/CSSStringValue.h

 // 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.
 
 #ifndef CSSStringValue_h
 #define CSSStringValue_h
 
 #include "core/css/CSSValue.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CSSStringValue : public CSSValue {
 public:
     static CSSStringValue* create(const String& str)
     {
         return new CSSStringValue(str);
     }
 
@@ skipping 12 matching lines @@
     CSSStringValue(const String&);
 
     String m_string;
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSStringValue, isStringValue());
 
 } // namespace blink
 
 #endif // CSSStringValue_h