Polymer elements added to third_party/polymer.

third_party/polymer/components/paper-menu-button/paper-menu-button-transition.css

Index: third_party/polymer/components/paper-menu-button/paper-menu-button-transition.css
diff --git a/third_party/polymer/components/paper-menu-button/paper-menu-button-transition.css b/third_party/polymer/components/paper-menu-button/paper-menu-button-transition.css
new file mode 100644
index 0000000000000000000000000000000000000000..6d1ba6e6ade46548cdf2d7954370bc271f088bb6
--- /dev/null
+++ b/third_party/polymer/components/paper-menu-button/paper-menu-button-transition.css
@@ -0,0 +1,19 @@
+/* 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 */
+
+:host(.paper-menu-button-transition) {
+  outline: none;
+  opacity: 0;
+  transition: transform 0.2s ease-in-out, opacity 0.2s ease-in;
+  -webkit-transition: -webkit-transform 0.2s ease-in-out, opacity 0.2s ease-in;
+}
+
+:host(.paper-menu-button-transition.paper-menu-button-opened) {
+  opacity: 1;
+  transform: none;
+  -webkit-transform: none;
+}