Remove third_party/polymer from .gitignore

third_party/polymer/v1_0/components/iron-icon/iron-icon.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">
-<link rel="import" href="../iron-meta/iron-meta.html">
-<link rel="import" href="../iron-flex-layout/iron-flex-layout.html">
-
-<!--
-
-The `iron-icon` element displays an icon. By default an icon renders as a 24px square.
-
-Example using src:
-
-    <iron-icon src="star.png"></iron-icon>
-
-Example setting size to 32px x 32px:
-
-    <iron-icon class="big" src="big_star.png"></iron-icon>
-
-    <style is="custom-style">
-      .big {
-        --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:
-
-    &lt;!-- import default iconset and iron-icon --&gt;
-    <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:
-
-    &lt;!-- import communication iconset and iron-icon --&gt;
-    <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`:
-
-    <iron-icon icon="fruit:cherry"></iron-icon>
-
-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](https://elements.polymer-project.org/elements/iron-icons?view=demo:demo/index.html) for the default set of icons.
-
-
-### 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`
-
-@group Iron Elements
-@element iron-icon
-@demo demo/index.html
-@hero hero.svg
-@homepage polymer.github.io
--->
-
-<dom-module id="iron-icon">
-
-  <style>
-    :host {
-      @apply(--layout-inline);
-      @apply(--layout-center-center);
-      position: relative;
-
-      vertical-align: middle;
-
-      fill: currentcolor;
-
-      width: var(--iron-icon-width, 24px);
-      height: var(--iron-icon-height, 24px);
-    }
-  </style>
-
-  <template>
-    <iron-meta id="meta" type="iconset"></iron-meta>
-  </template>
-
-  <script>
-
-    Polymer({
-
-      is: 'iron-icon',
-
-      properties: {
-
-        /**
-         * The name of the icon to use. The name should be of the form:
-         * `iconset_name:icon_name`.
-         */
-        icon: {
-          type: String,
-          observer: '_iconChanged'
-        },
-
-        /**
-         * The name of the theme to used, if one is specified by the
-         * iconset.
-         */
-        theme: {
-          type: String,
-          observer: '_updateIcon'
-        },
-
-        /**
-         * If using iron-icon without an iconset, you can set the src to be
-         * the URL of an individual icon image file. Note that this will take
-         * precedence over a given icon attribute.
-         */
-        src: {
-          type: String,
-          observer: '_srcChanged'
-        }
-      },
-
-      _DEFAULT_ICONSET: 'icons',
-
-      _iconChanged: function(icon) {
-        var parts = (icon || '').split(':');
-        this._iconName = parts.pop();
-        this._iconsetName = parts.pop() || this._DEFAULT_ICONSET;
-        this._updateIcon();
-      },
-
-      _srcChanged: function(src) {
-        this._updateIcon();
-      },
-
-      _usesIconset: function() {
-        return this.icon || !this.src;
-      },
-
-      _updateIcon: function() {
-        if (this._usesIconset()) {
-          if (this._iconsetName) {
-            this._iconset = this.$.meta.byKey(this._iconsetName);
-            if (this._iconset) {
-              this._iconset.applyIcon(this, this._iconName, this.theme);
-            } else {
-              this._warn(this._logf('_updateIcon', 'could not find iconset `'
-                + this._iconsetName + '`, did you import the iconset?'));
-            }
-          }
-        } else {
-          if (!this._img) {
-            this._img = document.createElement('img');
-            this._img.style.width = '100%';
-            this._img.style.height = '100%';
-          }
-          this._img.src = this.src;
-          Polymer.dom(this.root).appendChild(this._img);
-        }
-      }
-
-    });
-
-  </script>
-
-</dom-module>