[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/iron-flex-layout/iron-flex-layout.html

 <!--
 @license
 Copyright (c) 2015 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
 -->
 
 <link rel="import" href="../polymer/polymer.html">
 
+<!--
+The `<iron-flex-layout>` component provides simple ways to use [CSS flexible box layout](https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Flexible_boxes), also known as flexbox. This component provides two different ways to use flexbox:
+
+1. [Layout classes](https://github.com/PolymerElements/iron-flex-layout/tree/master/classes). The layout class stylesheet provides a simple set of class-based flexbox rules. Layout classes let you specify layout properties directly in markup.
+
+2. [Custom CSS mixins](https://github.com/PolymerElements/iron-flex-layout/blob/master/iron-flex-layout.html). The mixin stylesheet includes custom CSS mixins that can be applied inside a CSS rule using the `@apply` function.
+
+A complete [guide](https://elements.polymer-project.org/guides/flex-layout) to `<iron-flex-layout>` is available.
+
+@group Iron Elements
+@pseudoElement iron-flex-layout
+@demo demo/index.html
+-->
+
+<style>
+  /* IE 10 support for HTML5 hidden attr */
+  [hidden] {
+    display: none !important;
+  }
+</style>
+
 <style is="custom-style">
-
   :root {
 
     --layout: {
       display: -ms-flexbox;
       display: -webkit-flex;
       display: flex;
     };
 
     --layout-inline: {
       display: -ms-inline-flexbox;
       display: -webkit-inline-flex;
       display: inline-flex;
     };
 
     --layout-horizontal: {
-      /* @apply(--layout); */
-      display: -ms-flexbox;
-      display: -webkit-flex;
-      display: flex;
+      @apply(--layout);
 
       -ms-flex-direction: row;
       -webkit-flex-direction: row;
       flex-direction: row;
     };
 
     --layout-horizontal-reverse: {
+      @apply(--layout);
+
       -ms-flex-direction: row-reverse;
       -webkit-flex-direction: row-reverse;
       flex-direction: row-reverse;
     };
 
     --layout-vertical: {
-      /* @apply(--layout); */
-      display: -ms-flexbox;
-      display: -webkit-flex;
-      display: flex;
+      @apply(--layout);
 
       -ms-flex-direction: column;
       -webkit-flex-direction: column;
       flex-direction: column;
     };
 
     --layout-vertical-reverse: {
+      @apply(--layout);
+
       -ms-flex-direction: column-reverse;
       -webkit-flex-direction: column-reverse;
       flex-direction: column-reverse;
     };
 
     --layout-wrap: {
       -ms-flex-wrap: wrap;
       -webkit-flex-wrap: wrap;
       flex-wrap: wrap;
     };
@@ skipping 136 matching lines @@
       justify-content: space-around;
     };
 
     --layout-justified: {
       -ms-flex-pack: justify;
       -webkit-justify-content: space-between;
       justify-content: space-between;
     };
 
     --layout-center-center: {
-      /* @apply(--layout-center --layout-center-justified); */
-      -ms-flex-align: center;
-      -webkit-align-items: center;
-      align-items: center;
-      -ms-flex-pack: center;
-      -webkit-justify-content: center;
-      justify-content: center;
+      @apply(--layout-center);
+      @apply(--layout-center-justified);
     };
 
     /* self alignment */
 
     --layout-self-start: {
       -ms-align-self: flex-start;
       -webkit-align-self: flex-start;
       align-self: flex-start;
     };
 
@@ skipping 37 matching lines @@
       right: 0;
       bottom: 0;
       left: 0;
     };
 
     --layout-scroll: {
       -webkit-overflow-scrolling: touch;
       overflow: auto;
     };
 
+    --layout-fullbleed: {
+      margin: 0;
+      height: 100vh;
+    };
+
     /* fixed position */
 
-    --layout-fixed-bottom:,
-    --layout-fixed-left:,
-    --layout-fixed-right:,
     --layout-fixed-top: {
       position: fixed;
-    };
-
-    --layout-fixed-top: {
       top: 0;
       left: 0;
       right: 0;
     };
 
     --layout-fixed-right: {
+      position: fixed;
       top: 0;
       right: 0;
       bottom: 0;
     };
 
     --layout-fixed-bottom: {
+      position: fixed;
       right: 0;
       bottom: 0;
       left: 0;
     };
 
     --layout-fixed-left: {
+      position: fixed;
       top: 0;
       bottom: 0;
       left: 0;
     };
 
   }
 
 </style>