Initial implementation of AudioTrack, AudioTrackList, VideoTrack, and VideoTrackList.

Source/core/html/track/TrackBaseList.h

+// Copyright 2014 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 TrackBaseList_h
+#define TrackBaseList_h
+
+#include "core/dom/ActiveDOMObject.h"
+#include "core/events/EventTarget.h"
+#include "core/html/HTMLMediaElement.h"
+
+namespace WebCore {
+
+class GenericEventQueue;
+class TrackBase;
+
+class TrackBaseList : public RefCounted<TrackBaseList>, public EventTargetWithInlineData, public ActiveDOMObject {
+    REFCOUNTED_EVENT_TARGET(TrackBaseList);
+
+public:
+    explicit TrackBaseList(HTMLMediaElement*);
+    virtual ~TrackBaseList();
+
+    unsigned length() const { return m_tracks.size(); }
+    TrackBase* getByIndex(unsigned index) const;
+    TrackBase* getById(const AtomicString& id) const;
+    unsigned getIndex(const AtomicString& id) const;
+
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(change);
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(addtrack);
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(removetrack);
+
+    // EventTarget interface
+    virtual ExecutionContext* executionContext() const OVERRIDE;
+
+    // ActiveDOMObject interface
+    virtual bool hasPendingActivity() const OVERRIDE;
+    virtual void stop() OVERRIDE;
+
+    void shutdown();
+
+    void add(TrackBase*);
+    void remove(const String& id);
+    void removeAll();
+
+    void scheduleChangeEvent();
+
+private:
+    void scheduleTrackEvent(const AtomicString& eventName, PassRefPtr<TrackBase>);
+
+    bool m_shutdown;
+    Vector<RefPtr<TrackBase> > m_tracks;
+    OwnPtr<GenericEventQueue> m_asyncEventQueue;
+};
+
+}
+
+#endif