Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/HashChangeEvent.dartdoc

Index: lib/html/doc/interface/HashChangeEvent.dartdoc
diff --git a/lib/html/doc/interface/HashChangeEvent.dartdoc b/lib/html/doc/interface/HashChangeEvent.dartdoc
deleted file mode 100644
index c93ee4126b2379d97f2b84892b36b9e0c3ef35e2..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/HashChangeEvent.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 HashChangeEvent
-interface HashChangeEvent extends Event {
-
-  /** @domName HashChangeEvent.newURL */
-  final String newURL;
-
-  /** @domName HashChangeEvent.oldURL */
-  final String oldURL;
-
-  /** @domName HashChangeEvent.initHashChangeEvent */
-  void initHashChangeEvent(String type, bool canBubble, bool cancelable, String oldURL, String newURL);
-}