Roll Polymer to 1.3.1

third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html

Index: third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html
diff --git a/third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html b/third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html
index 09b4657ad98b1ec004f4021016546ca80c9b25b4..7315faf1c3036ce593292e83c33b817a7c91f94e 100644
--- a/third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html
+++ b/third_party/polymer/v1_0/components-chromium/iron-flex-layout/iron-flex-layout.html
@@ -11,11 +11,33 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 <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:
+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.
+1. [Layout classes](https://github.com/PolymerElements/iron-flex-layout/tree/master/iron-flex-layout-classes.html).
+The layout class stylesheet provides a simple set of class-based flexbox rules, that
+let you specify layout properties directly in markup. You must include this file
+in every element that needs to use them.
 
-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.
+Sample use:
+
+    <link rel="import" href="../iron-flex-layout/iron-flex-layout-classes.html">
+    <style is="custom-style" include="iron-flex iron-flex-alignment">
+
+    <div class="layout horizontal layout-start">
+      <div>cross axis start alignment</div>
+    </div>
+
+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.
+
+Please note that the old [/deep/ layout classes](https://github.com/PolymerElements/iron-flex-layout/tree/master/classes)
+are deprecated, and should not be used. To continue using layout properties
+directly in markup, please switch to using the new `dom-module`-based
+[layout classes](https://github.com/PolymerElements/iron-flex-layout/tree/master/iron-flex-layout-classes.html).
+Please note that the new version does not use `/deep/`, and therefore requires you
+to import the `dom-modules` in every element that needs to use them.
 
 A complete [guide](https://elements.polymer-project.org/guides/flex-layout) to `<iron-flex-layout>` is available.
 
@@ -217,7 +239,7 @@ A complete [guide](https://elements.polymer-project.org/guides/flex-layout) to `
     };
 
     --layout-around-justified: {
-      -ms-flex-pack: around;
+      -ms-flex-pack: distribute;
       -webkit-justify-content: space-around;
       justify-content: space-around;
     };