Roll Observatory packages and add a roll script

browser/lib/interop.js

Index: browser/lib/interop.js
diff --git a/browser/lib/interop.js b/browser/lib/interop.js
deleted file mode 100644
index ec02e5857ad195d2df1c15a768f83fda4b7fa098..0000000000000000000000000000000000000000
--- a/browser/lib/interop.js
+++ /dev/null
@@ -1,9 +0,0 @@
-// Copyright (c) 2013, 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.
-
-// TODO(jmesserly): remove this script after a deprecation period.
-if (typeof console == "object" && typeof console.warn == "function") {
-  console.warn('<script src="packages/browser/interop.js"> is no longer ' +
-      'needed for dart:js. See http://pub.dartlang.org/packages/browser.');
-}