[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js

 /**
  * @license
  * 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
  */
-// @version 0.7.5
+// @version 0.7.20
 if (typeof WeakMap === "undefined") {
   (function() {
     var defineProperty = Object.defineProperty;
     var counter = Date.now() % 1e9;
     var WeakMap = function() {
       this.name = "__st" + (Math.random() * 1e9 >>> 0) + (counter++ + "__");
     };
     WeakMap.prototype = {
       set: function(key, value) {
         var entry = key[this.name];
@@ skipping 17 matching lines @@
         var entry = key[this.name];
         if (!entry) return false;
         return entry[0] === key;
       }
     };
     window.WeakMap = WeakMap;
   })();
 }
 
 (function(global) {
+  if (global.JsMutationObserver) {
+    return;
+  }
   var registrationsTable = new WeakMap();
   var setImmediate;
   if (/Trident|Edge/.test(navigator.userAgent)) {
     setImmediate = setTimeout;
   } else if (window.setImmediate) {
     setImmediate = window.setImmediate;
   } else {
     var setImmediateQueue = [];
     var sentinel = String(Math.random());
     window.addEventListener("message", function(e) {
@@ skipping 275 matching lines @@
         record.nextSibling = nextSibling;
         forEachAncestorAndObserverEnqueueRecord(e.relatedNode, function(options) {
           if (!options.childList) return;
           return record;
         });
       }
       clearRecords();
     }
   };
   global.JsMutationObserver = JsMutationObserver;
-  if (!global.MutationObserver) global.MutationObserver = JsMutationObserver;
-})(this);
+  if (!global.MutationObserver) {
+    global.MutationObserver = JsMutationObserver;
+    JsMutationObserver._isPolyfilled = true;
+  }
+})(self);