Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/DataTransferItem.dartdoc

Index: lib/html/doc/interface/DataTransferItem.dartdoc
diff --git a/lib/html/doc/interface/DataTransferItem.dartdoc b/lib/html/doc/interface/DataTransferItem.dartdoc
deleted file mode 100644
index d5399173cdd65cfb7751d580a358bf0ffb53b5b7..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/DataTransferItem.dartdoc
+++ /dev/null
@@ -1,23 +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 DataTransferItem
-interface DataTransferItem {
-
-  /** @domName DataTransferItem.kind */
-  final String kind;
-
-  /** @domName DataTransferItem.type */
-  final String type;
-
-  /** @domName DataTransferItem.getAsFile */
-  Blob getAsFile();
-
-  /** @domName DataTransferItem.getAsString */
-  void getAsString([StringCallback callback]);
-}