Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/IDBIndex.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 IDBIndex
-interface IDBIndex {
-
-  /** @domName IDBIndex.keyPath */
-  final Dynamic keyPath;
-
-  /** @domName IDBIndex.multiEntry */
-  final bool multiEntry;
-
-  /** @domName IDBIndex.name */
-  final String name;
-
-  /** @domName IDBIndex.objectStore */
-  final IDBObjectStore objectStore;
-
-  /** @domName IDBIndex.unique */
-  final bool unique;
-
-  /** @domName IDBIndex.count */
-  IDBRequest count([key_OR_range]);
-
-  /** @domName IDBIndex.get */
-  IDBRequest get(key);
-
-  /** @domName IDBIndex.getKey */
-  IDBRequest getKey(key);
-
-  /** @domName IDBIndex.openCursor */
-  IDBRequest openCursor([key_OR_range, direction]);
-
-  /** @domName IDBIndex.openKeyCursor */
-  IDBRequest openKeyCursor([key_OR_range, direction]);
-}