[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/paper-material/README.md

+
+<!---
+
+This README is automatically generated from the comments in these files:
+paper-material.html
+
+Edit those files, and our readme bot will duplicate them over here!
+Edit this file, and the bot will squash your changes :)
+
+-->
+
+[![Build Status](https://travis-ci.org/PolymerElements/paper-material.svg?branch=master)](https://travis-ci.org/PolymerElements/paper-material)
+
+_[Demo and API Docs](https://elements.polymer-project.org/elements/paper-material)_
+
+
+##&lt;paper-material&gt;
+
+
+Material design: [Cards](https://www.google.com/design/spec/components/cards.html)
+
+`paper-material` is a container that renders two shadows on top of each other to
+create the effect of a lifted piece of paper.
+
+Example:
+
+    <paper-material elevation="1">
+      ... content ...
+    </paper-material>
+
+