Roll Polymer to 1.3.1

third_party/polymer/v1_0/components-chromium/iron-icon/README.md

-iron-icon
-=========
+
+<!---
 
+This README is automatically generated from the comments in these files:
+iron-icon.html
+
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+Edit this file, and the bot will squash your changes :)
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+-->
+
+[![Build status](https://travis-ci.org/PolymerElements/iron-icon.svg?branch=master)](https://travis-ci.org/PolymerElements/iron-icon)
+
+_[Demo and API docs](https://elements.polymer-project.org/elements/iron-icon)_
+
+
+##&lt;iron-icon&gt;
+
 The `iron-icon` element displays an icon. By default an icon renders as a 24px square.
 
 Example using src:
 
 ```html
 <iron-icon src="star.png"></iron-icon>
 ```
 
 Example setting size to 32px x 32px:
 
 ```html
 <iron-icon class="big" src="big_star.png"></iron-icon>
 
-<style>
+<style is="custom-style">
   .big {
-    height: 32px;
-    width: 32px;
+    --iron-icon-height: 32px;
+    --iron-icon-width: 32px;
   }
 </style>
 ```
 
 The iron elements include several sets of icons.
-To use the default set of icons, import  `iron-icons.html` and use the `icon` attribute to specify an icon:
+To use the default set of icons, import `iron-icons.html` and use the `icon` attribute to specify an icon:
 
 ```html
-<!-- import default iconset and iron-icon -->
 <link rel="import" href="/components/iron-icons/iron-icons.html">
 
 <iron-icon icon="menu"></iron-icon>
 ```
 
-To use a different built-in set of icons, import  `iron-icons/<iconset>-icons.html`, and
-specify the icon as `<iconset>:<icon>`. For example:
+To use a different built-in set of icons, import the specific `iron-icons/<iconset>-icons.html`, and
+specify the icon as `<iconset>:<icon>`. For example, to use a communication icon, you would
+use:
 
 ```html
-<!-- import communication iconset and iron-icon -->
 <link rel="import" href="/components/iron-icons/communication-icons.html">
 
 <iron-icon icon="communication:email"></iron-icon>
 ```
 
 You can also create custom icon sets of bitmap or SVG icons.
 
 Example of using an icon named `cherry` from a custom iconset with the ID `fruit`:
 
 ```html
 <iron-icon icon="fruit:cherry"></iron-icon>
 ```
 
-See [iron-iconset](#iron-iconset) and [iron-iconset-svg](#iron-iconset-svg) for more information about
+See [iron-iconset](iron-iconset) and [iron-iconset-svg](iron-iconset-svg) for more information about
 how to create a custom iconset.
 
-See [iron-icons](http://www.polymer-project.org/components/iron-icons/demo.html) for the default set of icons.
+See the [iron-icons demo](iron-icons?view=demo:demo/index.html) to see the icons available
+in the various iconsets.
+
+To load a subset of icons from one of the default `iron-icons` sets, you can
+use the [poly-icon](https://poly-icon.appspot.com/) tool. It allows you
+to select individual icons, and creates an iconset from them that you can
+use directly in your elements.
+
+### Styling
+
+The following custom properties are available for styling:
+
+| Custom property | Description | Default |
+| --- | --- | --- |
+| `--iron-icon-width` | Width of the icon | `24px` |
+| `--iron-icon-height` | Height of the icon | `24px` |
+| `--iron-icon-fill-color` | Fill color of the svg icon | `currentcolor` |
+| `--iron-icon-stroke-color` | Stroke color of the svg icon | none |
+
+