Implement AudioTrack, AudioTrackList, VideoTrack, and VideoTrackList

Source/core/html/track/VideoTrack.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/VideoTrack.h"
+
+#include "core/html/HTMLMediaElement.h"
+
+namespace WebCore {
+
+VideoTrack::VideoTrack(const String& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language)
+    : TrackBase(TrackBase::VideoTrack, label, language, id)
+    , m_selected(false)
+{
+    ScriptWrappable::init(this);
+    setKind(kind);
+}
+
+VideoTrack::~VideoTrack()
+{
+}
+
+void VideoTrack::setSelected(bool selected)
+{
+    if (selected == m_selected)
+        return;
+
+    m_selected = selected;
+    if (mediaElement()) {
+        blink::WebMediaPlayer::TrackId selectedTrackId = trackId();
+        mediaElement()->selectedVideoTrackChanged(selected ? &selectedTrackId : 0);
+    }
+}
+
+const AtomicString& VideoTrack::alternativeKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("alternative", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& VideoTrack::captionsKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("captions", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& VideoTrack::mainKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("main", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& VideoTrack::signKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("sign", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& VideoTrack::subtitlesKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("subtitles", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+const AtomicString& VideoTrack::commentaryKeyword()
+{
+    DEFINE_STATIC_LOCAL(const AtomicString, keyword, ("commentary", AtomicString::ConstructFromLiteral));
+    return keyword;
+}
+
+bool VideoTrack::isValidKind(const AtomicString& kind) const
+{
+    return (kind == alternativeKeyword())
+        || (kind == captionsKeyword())
+        || (kind == mainKeyword())
+        || (kind == signKeyword())
+        || (kind == subtitlesKeyword())
+        || (kind == commentaryKeyword());
+}
+
+AtomicString VideoTrack::defaultKind() const
+{
+    return emptyAtom;
+}
+
+}