Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/MediaStreamTrack.dartdoc

Index: lib/html/doc/interface/MediaStreamTrack.dartdoc
diff --git a/lib/html/doc/interface/MediaStreamTrack.dartdoc b/lib/html/doc/interface/MediaStreamTrack.dartdoc
deleted file mode 100644
index bd0b45c512e3ad6e532199dd3000b99e779478f9..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/MediaStreamTrack.dartdoc
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING:
-//   This file contains documentation that is merged into the real source.
-//   Do not make code changes here.
-
-/// @domName MediaStreamTrack
-interface MediaStreamTrack {
-
-  /** @domName MediaStreamTrack.enabled */
-  bool enabled;
-
-  /** @domName MediaStreamTrack.kind */
-  final String kind;
-
-  /** @domName MediaStreamTrack.label */
-  final String label;
-}