[Oilpan] Prepare full definition of classes before using Member

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

 /*
  * Copyright (C) 2013 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 76 matching lines @@
     String status() const;
     ScriptPromise loaded(ScriptState* scriptState) { return fontStatusPromise(scriptState); }
 
     ScriptPromise load(ScriptState*);
 
     LoadStatus loadStatus() const { return m_status; }
     void setLoadStatus(LoadStatus);
     void setError(DOMException* = nullptr);
     DOMException* error() const { return m_error; }
     FontTraits traits() const;
-    CSSFontFace* cssFontFace() { return m_cssFontFace.get(); }
+    CSSFontFace* cssFontFace() const;
 
     DECLARE_VIRTUAL_TRACE();
 
     bool hadBlankText() const;
 
     class LoadFontCallback : public RefCountedWillBeGarbageCollectedFinalized<LoadFontCallback> {
     public:
         virtual ~LoadFontCallback() { }
         virtual void notifyLoaded(FontFace*) = 0;
         virtual void notifyError(FontFace*) = 0;
@@ skipping 37 matching lines @@
     PersistentWillBeMember<LoadedProperty> m_loadedProperty;
     OwnPtrWillBeMember<CSSFontFace> m_cssFontFace;
     WillBeHeapVector<RefPtrWillBeMember<LoadFontCallback>> m_callbacks;
 };
 
 using FontFaceArray = WillBeHeapVector<RefPtrWillBeMember<FontFace>>;
 
 } // namespace blink
 
 #endif // FontFace_h