Add SourceBuffer implementations of Audio/VideoTracks

third_party/WebKit/Source/modules/mediasource/VideoTrackSourceBuffer.h

+// Copyright 2016 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 VideoTrackSourceBuffer_h
+#define VideoTrackSourceBuffer_h
+
+#include "platform/Supplementable.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class VideoTrack;
+class SourceBuffer;
+
+class VideoTrackSourceBuffer final : public GarbageCollectedFinalized<VideoTrackSourceBuffer>, public HeapSupplement<VideoTrack> {
+    USING_GARBAGE_COLLECTED_MIXIN(VideoTrackSourceBuffer);
+public:
+    static VideoTrackSourceBuffer& from(VideoTrack&);
+    virtual ~VideoTrackSourceBuffer();
+
+    static SourceBuffer* sourceBuffer(VideoTrack&);
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    static const char* supplementName();
+    explicit VideoTrackSourceBuffer(SourceBuffer*);
+
+    WeakMember<SourceBuffer> m_sourceBuffer;
+};
+
+} // namespace blink
+
+#endif