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

Source/core/html/HTMLSourceElement.h

 /*
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 #ifndef HTMLSourceElement_h
 #define HTMLSourceElement_h
 
+#include "core/css/MediaQueryListListener.h"
 #include "core/html/HTMLElement.h"
 #include "platform/Timer.h"
 
 namespace WebCore {
 
 template<typename T> class EventSender;
 typedef EventSender<HTMLSourceElement> SourceEventSender;
 
 class HTMLSourceElement FINAL : public HTMLElement {
 public:
+    class Listener : public MediaQueryListListener {

[esprehn, 2014/07/02 21:15:42]

Put this in the cpp file please.

class Listener; here and the rest in the cpp.

+    public:
+        explicit Listener(HTMLSourceElement* element) : m_element(element) { }
+        virtual void call() OVERRIDE
+        {
+            if (m_element)
+                m_element->notifyMediaQueryChanged();
+        }
+
+        void clearElement() { m_element = nullptr; }
+    private:
+        HTMLSourceElement* m_element;

[sof, 2014/07/02 21:22:18]

RawPtrWillBeMember<> + add a trace() method which traces it & decorate Listener
with FINAL?

+    };
+
     DECLARE_NODE_FACTORY(HTMLSourceElement);
     virtual ~HTMLSourceElement();
 
     const AtomicString& type() const;
     void setSrc(const String&);
     void setType(const AtomicString&);
 
     void scheduleErrorEvent();
     void cancelPendingErrorEvent();
 
     void dispatchPendingEvent(SourceEventSender*);
 
+    bool mediaQueryMatches() const;
+
 private:
     explicit HTMLSourceElement(Document&);
 
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
+
+    void notifyMediaQueryChanged();
+
+    RefPtrWillBeRawPtr<MediaQueryList> m_mediaQueryList;

[sof, 2014/07/02 21:22:18]

I think you need RefPtrWillBeMember<>, as you want to make sure the GCed object
is kept track of. You'll need to add an OVERRIDE trace() method to have it be
traced.

+    RefPtrWillBeRawPtr<Listener> m_listener;

[sof, 2014/07/02 21:22:18]

RefPtrWillBeMember<>

 };
 
 } // namespace WebCore
 
 #endif