Add paper-dropdown and paper-dropdown-menu and run reproduce.sh

third_party/polymer/components/paper-dropdown/paper-dropdown-transition.css

 /* 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 */
 
-html /deep/ core-icon {
-  display: inline-block;
-  vertical-align: middle;
-  background-repeat: no-repeat;
-  fill: currentcolor;
-  position: relative;
-  height: 24px;
-  width: 24px;
+:host(.core-transition) #ripple,
+:host(.core-transition) #background {
+  opacity: 0;
+}
+
+:host(.core-transition) #scroller {
+  opacity: 0;
 }