[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js

Index: polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js
diff --git a/polymer_1.0.4/bower_components/webcomponentsjs/MutationObserver.js b/polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js
similarity index 98%
copy from polymer_1.0.4/bower_components/webcomponentsjs/MutationObserver.js
copy to polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js
index b8fb3cf47aeaa4ac153630fefb84370d42bef62c..3fc9de8c2282ef1a53a7d54948a0b25d28a03bf5 100644
--- a/polymer_1.0.4/bower_components/webcomponentsjs/MutationObserver.js
+++ b/polymer_1.2.3/bower_components/webcomponentsjs/MutationObserver.js
@@ -7,7 +7,7 @@
  * 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;
@@ -45,6 +45,9 @@ if (typeof WeakMap === "undefined") {
 }
 
 (function(global) {
+  if (global.JsMutationObserver) {
+    return;
+  }
   var registrationsTable = new WeakMap();
   var setImmediate;
   if (/Trident|Edge/.test(navigator.userAgent)) {
@@ -340,5 +343,8 @@ if (typeof WeakMap === "undefined") {
     }
   };
   global.JsMutationObserver = JsMutationObserver;
-  if (!global.MutationObserver) global.MutationObserver = JsMutationObserver;
-})(this);
+  if (!global.MutationObserver) {
+    global.MutationObserver = JsMutationObserver;
+    JsMutationObserver._isPolyfilled = true;
+  }
+})(self);