Pull web-animations-js into third-party via the third_party/polymer/reproduce.sh script. Add necess…

third_party/web-animations-js/sources/src/deprecation.js

+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+//     You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//     See the License for the specific language governing permissions and
+// limitations under the License.
+
+(function(shared) {
+
+  var silenced = {};
+
+  shared.isDeprecated = function(feature, date, advice, plural) {
+    var auxVerb = plural ? 'are' : 'is';
+    var today = new Date();
+    var expiry = new Date(date);
+    expiry.setMonth(expiry.getMonth() + 3); // 3 months grace period
+
+    if (today < expiry) {
+      if (!(feature in silenced)) {
+        console.warn('Web Animations: ' + feature + ' ' + auxVerb + ' deprecated and will stop working on ' + expiry.toDateString() + '. ' + advice);
+      }
+      silenced[feature] = true;
+      return false;
+    } else {
+      return true;
+    }
+  };
+
+  shared.deprecated = function(feature, date, advice, plural) {
+    if (shared.isDeprecated(feature, date, advice, plural)) {
+      throw new Error(feature + ' ' + auxVerb + ' no longer supported. ' + advice);
+    }
+  };
+
+})(webAnimationsShared);