[Oilpan] Prepare full definition of classes before using Member

third_party/WebKit/Source/core/dom/DocumentOrderedMap.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple 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 50 matching lines @@
     Element* getElementByLabelForAttribute(const AtomicString&, const TreeScope*) const;
 
     DECLARE_TRACE();
 
 private:
     template<bool keyMatches(const AtomicString&, const Element&)>
     Element* get(const AtomicString&, const TreeScope*) const;
 
     class MapEntry : public NoBaseWillBeGarbageCollected<MapEntry> {
     public:
-        explicit MapEntry(Element* firstElement)
-            : element(firstElement)
-            , count(1)
-        {
-        }
+        explicit MapEntry(Element*);
 
         DECLARE_TRACE();
 
         RawPtrWillBeMember<Element> element;
         unsigned count;
         WillBeHeapVector<RawPtrWillBeMember<Element>> orderedList;
     };
 
     using Map = WillBeHeapHashMap<AtomicString, OwnPtrWillBeMember<MapEntry>>;
 
     mutable Map m_map;
 };
 
 inline bool DocumentOrderedMap::contains(const AtomicString& id) const
 {
     return m_map.contains(id);
 }
 
 inline bool DocumentOrderedMap::containsMultiple(const AtomicString& id) const
 {
     Map::const_iterator it = m_map.find(id);
     return it != m_map.end() && it->value->count > 1;
 }
 
 } // namespace blink
 
 #endif // DocumentOrderedMap_h