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

Source/core/html/track/AudioTrack.cpp

+// 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/AudioTrack.h"
+
+#include "core/html/HTMLMediaElement.h"
+
+namespace WebCore {
+
+AudioTrack::AudioTrack(HTMLMediaElement* mediaElement, const String& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language)
+    : TrackBase(TrackBase::AudioTrack, label, language, id)
+    , m_enabled(false)
+{
+    ASSERT(mediaElement);
+    ASSERT(!id.isEmpty());
+
+    ScriptWrappable::init(this);
+    setKind(kind);
+    setMediaElement(mediaElement);
+}
+
+AudioTrack::~AudioTrack()
+{
+}
+
+void AudioTrack::setEnabled(bool enabled)
+{
+    if (enabled == m_enabled)
+        return;
+
+    m_enabled = enabled;
+
+    if (mediaElement())
+        mediaElement()->audioTrackChanged(id());
+}
+
+const AtomicString& AudioTrack::alternativeKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("alternative", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& AudioTrack::descriptionsKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("descriptions", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& AudioTrack::mainKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("main", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& AudioTrack::mainDescriptionsKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("main-desc", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& AudioTrack::translationKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("translation", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& AudioTrack::commentaryKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("commentary", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+bool AudioTrack::isValidKind(const AtomicString& kind) const
+{
+    return (kind == alternativeKeyword())
+        || (kind == descriptionsKeyword())
+        || (kind == mainKeyword())
+        || (kind == mainDescriptionsKeyword())
+        || (kind == translationKeyword())
+        || (kind == commentaryKeyword());
+}
+
+AtomicString AudioTrack::defaultKind() const
+{
+    return emptyAtom;
+}
+
+}