Chromecast: Add media_caps.h to unblock internal builds

chromecast/media/base/media_caps.h

+// 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.
+
+#ifndef CHROMECAST_MEDIA_BASE_MEDIA_CAPS_
+#define CHROMECAST_MEDIA_BASE_MEDIA_CAPS_
+
+namespace media {
+
+bool HdmiSinkSupportsAC3();
+bool HdmiSinkSupportsDTS();
+bool HdmiSinkSupportsDTSHD();
+bool HdmiSinkSupportsEAC3();
+bool HdmiSinkSupportsPcmSurroundSound();
+
+}  // namespace media
+
+#endif  // CHROMECAST_MEDIA_BASE_MEDIA_CAPS_
+