Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/SessionDescription.dartdoc

Index: lib/html/doc/interface/SessionDescription.dartdoc
diff --git a/lib/html/doc/interface/SessionDescription.dartdoc b/lib/html/doc/interface/SessionDescription.dartdoc
deleted file mode 100644
index af8e98f8a29c9b447b19dab09a79535cb2e3862f..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/SessionDescription.dartdoc
+++ /dev/null
@@ -1,19 +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 SessionDescription
-interface SessionDescription default _SessionDescriptionFactoryProvider {
-
-  SessionDescription(String sdp);
-
-  /** @domName SessionDescription.addCandidate */
-  void addCandidate(IceCandidate candidate);
-
-  /** @domName SessionDescription.toSdp */
-  String toSdp();
-}