Add dummy dart:html library for documentation.

lib/html/doc/nodoc-src/_PeerConnection00FactoryProvider.dart

Index: lib/html/doc/nodoc-src/_PeerConnection00FactoryProvider.dart
diff --git a/lib/html/doc/nodoc-src/_PeerConnection00FactoryProvider.dart b/lib/html/doc/nodoc-src/_PeerConnection00FactoryProvider.dart
new file mode 100644
index 0000000000000000000000000000000000000000..13f21195dfb9676540d1a822f71e0c030f227ef9
--- /dev/null
+++ b/lib/html/doc/nodoc-src/_PeerConnection00FactoryProvider.dart
@@ -0,0 +1,8 @@
+// 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.
+
+class _PeerConnection00FactoryProvider {
+  factory PeerConnection00(String serverConfiguration, IceCallback iceCallback)
+      => null;
+}