Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components/polymer/src/micro/mixins.html

Index: third_party/polymer/v0_8/components/polymer/src/micro/mixins.html
diff --git a/third_party/polymer/v0_8/components/polymer/src/micro/mixins.html b/third_party/polymer/v0_8/components/polymer/src/micro/mixins.html
new file mode 100644
index 0000000000000000000000000000000000000000..4f0b27462a495de3faa7be40a51006d4b40ae2ce
--- /dev/null
+++ b/third_party/polymer/v0_8/components/polymer/src/micro/mixins.html
@@ -0,0 +1,40 @@
+<!--
+@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
+-->
+<script>
+
+  /**
+   * Automatically extend using objects referenced in `mixins` array. 
+   * 
+   *     Polymer({
+   *     
+   *       mixins: [
+   *         someMixinObject
+   *       ]
+   *     
+   *       ...
+   *     
+   *     });
+   * 
+   * @class base feature: mixins
+   */
+
+  Polymer.Base._addFeature({
+
+    _prepMixins: function() {
+      if (this.mixins) {
+        this.mixins.forEach(function(m) {
+          Polymer.Base.extend(this, m);
+        }, this);
+      }
+    }
+
+  });
+
+</script>