Remove unneeded files from third_party/polymer.

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

-
-<!---
-
-This README is automatically generated from the comments in these files:
-iron-icons.html
-
-Edit those files, and our readme bot will duplicate them over here!
-Edit this file, and the bot will squash your changes :)
-
-The bot does some handling of markdown. Please file a bug if it does the wrong
-thing! https://github.com/PolymerLabs/tedium/issues
-
--->
-
-[![Build Status](https://travis-ci.org/PolymerElements/iron-icons.svg?branch=master)](https://travis-ci.org/PolymerElements/iron-icons)
-
-_[Demo and API Docs](https://elements.polymer-project.org/elements/iron-icons)_
-
-
-##&lt;iron-icons&gt;
-
-`iron-icons` is a utility import that includes the definition for the `iron-icon` element, `iron-iconset-svg` element, as well as an import for the default icon set.
-
-The `iron-icons` directory also includes imports for additional icon sets that can be loaded into your project.
-
-Example loading icon set:
-
-```html
-<link rel="import" href="../iron-icons/maps-icons.html">
-```
-
-To use an icon from one of these sets, first prefix your `iron-icon` with the icon set name, followed by a colon, ":", and then the icon id.
-
-Example using the directions-bus icon from the maps icon set:
-
-```html
-<iron-icon icon="maps:directions-bus"></iron-icon>
-```
-
-See [iron-icon](#iron-icon) for more information about working with icons.
-
-See [iron-iconset](#iron-iconset) and [iron-iconset-svg](#iron-iconset-svg) for more information about how to create a custom iconset.
-
-