Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/MediaController.dartdoc

-// 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 MediaController
-interface MediaController extends EventTarget default _MediaControllerFactoryProvider {
-
-  MediaController();
-
-  /** @domName MediaController.buffered */
-  final TimeRanges buffered;
-
-  /** @domName MediaController.currentTime */
-  num currentTime;
-
-  /** @domName MediaController.defaultPlaybackRate */
-  num defaultPlaybackRate;
-
-  /** @domName MediaController.duration */
-  final num duration;
-
-  /** @domName MediaController.muted */
-  bool muted;
-
-  /** @domName MediaController.paused */
-  final bool paused;
-
-  /** @domName MediaController.playbackRate */
-  num playbackRate;
-
-  /** @domName MediaController.played */
-  final TimeRanges played;
-
-  /** @domName MediaController.seekable */
-  final TimeRanges seekable;
-
-  /** @domName MediaController.volume */
-  num volume;
-
-  /** @domName MediaController.addEventListener */
-  void $dom_addEventListener(String type, EventListener listener, [bool useCapture]);
-
-  /** @domName MediaController.dispatchEvent */
-  bool $dom_dispatchEvent(Event evt);
-
-  /** @domName MediaController.pause */
-  void pause();
-
-  /** @domName MediaController.play */
-  void play();
-
-  /** @domName MediaController.removeEventListener */
-  void $dom_removeEventListener(String type, EventListener listener, [bool useCapture]);
-}