Notify <picture> elements when a media query (potentially) changes

Source/core/css/MediaQueryListListener.h

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 35 matching lines @@
 
     virtual void call();
 
     // Used to keep the MediaQueryList alive and registered with the MediaQueryMatcher
     // as long as the listener exists.
     void setMediaQueryList(MediaQueryList* query) { m_query = query; }
     void clearMediaQueryList() { m_query = nullptr; }
 
     bool operator==(const MediaQueryListListener& other) const { return m_function.isNull() ? this == &other : m_function == other.m_function; }
 
-    void trace(Visitor* visitor) { visitor->trace(m_query); }
+    virtual void trace(Visitor* visitor) { visitor->trace(m_query); }

[esprehn, 2014/07/02 22:40:11]

OVERRIDE

 
 protected:
     MediaQueryListListener();
 
     RefPtrWillBeMember<MediaQueryList> m_query;
 
 private:
     MediaQueryListListener(ScriptState*, const ScriptValue&);
 
     RefPtr<ScriptState> m_scriptState;
     ScriptValue m_function;
 };
 
 }
 
 #endif // MediaQueryListListener_h