Implement AudioTrack, AudioTrackList, VideoTrack, and VideoTrackList

Source/core/html/track/TrackBase.h

Index: Source/core/html/track/TrackBase.h
diff --git a/Source/core/html/track/TrackBase.h b/Source/core/html/track/TrackBase.h
index d3625f076e5d349e4e089b20a86f5ba9e4c8b9c5..3878c6ec1fbc3d128c5fc2d6dc7cb60ea4424782 100644
--- a/Source/core/html/track/TrackBase.h
+++ b/Source/core/html/track/TrackBase.h
@@ -32,6 +32,8 @@
 
 namespace WebCore {
 
+class HTMLMediaElement;
+
 class TrackBase : public RefCountedWillBeRefCountedGarbageCollected<TrackBase> {
 public:
     virtual ~TrackBase();
@@ -48,13 +50,16 @@ public:
     AtomicString language() const { return m_language; }
     void setLanguage(const AtomicString& language) { m_language = language; }
 
-    AtomicString id() const { return m_id; }
-    void setId(const AtomicString& id) { m_id = id; }
+    String id() const { return m_id; }
+    void setId(const String& id) { m_id = id; }
+
+    void setMediaElement(HTMLMediaElement* mediaElement) { m_mediaElement = mediaElement; }
+    HTMLMediaElement* mediaElement() const { return m_mediaElement; }
 
     virtual void trace(Visitor*) { }
 
 protected:
-    TrackBase(Type, const AtomicString& label, const AtomicString& language, const AtomicString& id);
+    TrackBase(Type, const AtomicString& label, const AtomicString& language, const String& id);
 
     virtual bool isValidKind(const AtomicString&) const = 0;
     virtual AtomicString defaultKind() const = 0;
@@ -64,7 +69,8 @@ private:
     AtomicString m_kind;
     AtomicString m_label;
     AtomicString m_language;
-    AtomicString m_id;
+    String m_id;
+    HTMLMediaElement* m_mediaElement;
 };
 
 } // namespace WebCore