Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/OverflowEvent.dartdoc

Index: lib/html/doc/interface/OverflowEvent.dartdoc
diff --git a/lib/html/doc/interface/OverflowEvent.dartdoc b/lib/html/doc/interface/OverflowEvent.dartdoc
deleted file mode 100644
index 63d630988731bc6cb0fb268dd71bbe05521e78be..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/OverflowEvent.dartdoc
+++ /dev/null
@@ -1,26 +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 OverflowEvent
-interface OverflowEvent extends Event {
-
-  static final int BOTH = 2;
-
-  static final int HORIZONTAL = 0;
-
-  static final int VERTICAL = 1;
-
-  /** @domName OverflowEvent.horizontalOverflow */
-  final bool horizontalOverflow;
-
-  /** @domName OverflowEvent.orient */
-  final int orient;
-
-  /** @domName OverflowEvent.verticalOverflow */
-  final bool verticalOverflow;
-}