Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/TrackElement.dartdoc

Index: lib/html/doc/interface/TrackElement.dartdoc
diff --git a/lib/html/doc/interface/TrackElement.dartdoc b/lib/html/doc/interface/TrackElement.dartdoc
deleted file mode 100644
index 2fc0f1acdfa7031129a3e0ef4360b86da5811e2e..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/TrackElement.dartdoc
+++ /dev/null
@@ -1,42 +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 HTMLTrackElement
-interface TrackElement extends Element default _Elements {
-
-  TrackElement();
-
-  static final int ERROR = 3;
-
-  static final int LOADED = 2;
-
-  static final int LOADING = 1;
-
-  static final int NONE = 0;
-
-  /** @domName HTMLTrackElement.defaultValue */
-  bool defaultValue;
-
-  /** @domName HTMLTrackElement.kind */
-  String kind;
-
-  /** @domName HTMLTrackElement.label */
-  String label;
-
-  /** @domName HTMLTrackElement.readyState */
-  final int readyState;
-
-  /** @domName HTMLTrackElement.src */
-  String src;
-
-  /** @domName HTMLTrackElement.srclang */
-  String srclang;
-
-  /** @domName HTMLTrackElement.track */
-  final TextTrack track;
-}