Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/template_binding/js/microtask.js

Index: observatory_pub_packages/template_binding/js/microtask.js
===================================================================
--- observatory_pub_packages/template_binding/js/microtask.js	(revision 0)
+++ observatory_pub_packages/template_binding/js/microtask.js	(working copy)
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+ */
+
+(function(scope) {
+
+var iterations = 0;
+var callbacks = [];
+var twiddle = document.createTextNode('');
+
+function endOfMicrotask(callback) {
+  twiddle.textContent = iterations++;
+  callbacks.push(callback);
+}
+
+function atEndOfMicrotask() {
+  while (callbacks.length) {
+    callbacks.shift()();
+  }
+}
+
+new (window.MutationObserver || JsMutationObserver)(atEndOfMicrotask)
+  .observe(twiddle, {characterData: true})
+  ;
+
+// exports
+scope.endOfMicrotask = endOfMicrotask;
+// bc 
+Platform.endOfMicrotask = endOfMicrotask;
+
+})(Polymer);
+