Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/TreeWalker.dartdoc

Index: lib/html/doc/interface/TreeWalker.dartdoc
diff --git a/lib/html/doc/interface/TreeWalker.dartdoc b/lib/html/doc/interface/TreeWalker.dartdoc
deleted file mode 100644
index 1d2f728b811e6b851811c874f9e4dfbcaaaf59da..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/TreeWalker.dartdoc
+++ /dev/null
@@ -1,47 +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 TreeWalker
-interface TreeWalker {
-
-  /** @domName TreeWalker.currentNode */
-  Node currentNode;
-
-  /** @domName TreeWalker.expandEntityReferences */
-  final bool expandEntityReferences;
-
-  /** @domName TreeWalker.filter */
-  final NodeFilter filter;
-
-  /** @domName TreeWalker.root */
-  final Node root;
-
-  /** @domName TreeWalker.whatToShow */
-  final int whatToShow;
-
-  /** @domName TreeWalker.firstChild */
-  Node firstChild();
-
-  /** @domName TreeWalker.lastChild */
-  Node lastChild();
-
-  /** @domName TreeWalker.nextNode */
-  Node nextNode();
-
-  /** @domName TreeWalker.nextSibling */
-  Node nextSibling();
-
-  /** @domName TreeWalker.parentNode */
-  Node parentNode();
-
-  /** @domName TreeWalker.previousNode */
-  Node previousNode();
-
-  /** @domName TreeWalker.previousSibling */
-  Node previousSibling();
-}