Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/File.dartdoc

Index: lib/html/doc/interface/File.dartdoc
diff --git a/lib/html/doc/interface/File.dartdoc b/lib/html/doc/interface/File.dartdoc
deleted file mode 100644
index e11e9460fd2aba00369f1cfc13ed96c4a1cb5128..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/File.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 File
-interface File extends Blob {
-
-  /** @domName File.lastModifiedDate */
-  final Date lastModifiedDate;
-
-  /** @domName File.name */
-  final String name;
-
-  /** @domName File.webkitRelativePath */
-  final String webkitRelativePath;
-}