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

Source/core/html/track/AudioTrackList.cpp

Index: Source/core/html/track/AudioTrackList.cpp
diff --git a/Source/core/html/track/AudioTrackList.cpp b/Source/core/html/track/AudioTrackList.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..00225d03f4bf0492383b7ac65bff1c468ca8ba1c
--- /dev/null
+++ b/Source/core/html/track/AudioTrackList.cpp
@@ -0,0 +1,55 @@
+// 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.
+
+#include "config.h"
+#include "core/html/track/AudioTrackList.h"
+
+#include "core/html/HTMLMediaElement.h"
+#include "core/html/track/AudioTrack.h"
+
+namespace WebCore {
+
+PassRefPtrWillBeRawPtr<AudioTrackList> AudioTrackList::create(HTMLMediaElement* mediaElement)
+{
+    RefPtrWillBeRawPtr<AudioTrackList> trackList(adoptRefWillBeRefCountedGarbageCollected(new AudioTrackList(mediaElement)));
+    trackList->suspendIfNeeded();
+    return trackList.release();
+}
+
+AudioTrackList::~AudioTrackList()
+{
+}
+
+AudioTrackList::AudioTrackList(HTMLMediaElement* mediaElement)
+    : TrackBaseList(mediaElement)
+{
+    ScriptWrappable::init(this);
+}
+
+AudioTrack* AudioTrackList::anonymousIndexedGetter(unsigned index) const
+{
+    return static_cast<AudioTrack*>(getByIndex(index));
+}
+
+AudioTrack* AudioTrackList::getTrackById(const AtomicString& id) const
+{
+    return static_cast<AudioTrack*>(getById(id));
+}
+
+bool AudioTrackList::hasEnabledTrack() const
+{
+    for (unsigned i = 0; i < length(); ++i) {
+        if (anonymousIndexedGetter(i)->enabled())
+            return true;
+    }
+
+    return false;
+}
+
+const AtomicString& AudioTrackList::interfaceName() const
+{
+    return EventTargetNames::AudioTrackList;
+}
+
+}