Revert "Polymer elements added to third_party/polymer."

third_party/polymer/components/core-icon/core-icon.html

-<!--
-Copyright (c) 2014 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
--->
-<!--
-
-The `core-icon` element displays an icon. By default an icon renders as 24px square.
-
-Example using src:
-
-    <core-icon src="star.png"></core-icon>
-
-Example setting size to 32px x 32px:
-
-    <core-icon class="big" src="big_star.png"></core-icon>
-
-    <style>
-      .big {
-        height: 32px;
-        width: 32px;
-      }
-    </style>
-
-Example using icon from default iconset:
-
-    <core-icon icon="menu"></core-icon>
-
-Example using icon `cherry` from custom iconset `fruit`:
-
-    <core-icon icon="fruit:cherry"></core-icon>
-
-See [core-iconset](#core-iconset) and [core-iconset-svg](#core-iconset-svg) for more information about
-how to use a custom iconset.
-
-See [core-icons](http://www.polymer-project.org/components/core-icons/demo.html) for the default set of icons. To use the default set of icons you'll need to include an import for `core-icons.html`. To use a different built-in set of icons, you'll need to include an import for `core-icons/iconsets/<iconset>.html`.
-
-@group Polymer Core Elements
-@element core-icon
-@homepage polymer.github.io
--->
-<link rel="import" href="../core-iconset/core-iconset.html">
-
-<link rel="stylesheet" href="core-icon.css" shim-shadowdom>
-
-<polymer-element name="core-icon" attributes="src icon alt">
-<script>
-(function() {
-  
-  // mono-state
-  var meta;
-  
-  Polymer('core-icon', {
-
-    /**
-     * The URL of an image for the icon. If the src property is specified,
-     * the icon property should not be.
-     *
-     * @attribute src
-     * @type string
-     * @default ''
-     */
-    src: '',
-
-    /**
-     * Specifies the icon name or index in the set of icons available in
-     * the icon's icon set. If the icon property is specified,
-     * the src property should not be.
-     *
-     * @attribute icon
-     * @type string
-     * @default ''
-     */
-    icon: '',
-
-    /**
-     * Alternative text content for accessibility support.
-     * If alt is present and not empty, it will set the element's role to img and add an aria-label whose content matches alt.
-     * If alt is present and is an empty string, '', it will hide the element from the accessibility layer
-     * If alt is not present, it will set the element's role to img and the element will fallback to using the icon attribute for its aria-label.
-     * 
-     * @attribute alt
-     * @type string
-     * @default ''
-     */
-    alt: null,
-
-    observe: {
-      'icon': 'updateIcon',
-      'alt': 'updateAlt'
-    },
-
-    defaultIconset: 'icons',
-
-    ready: function() {
-      if (!meta) {
-        meta = document.createElement('core-iconset');
-      }
-
-      // Allow user-provided `aria-label` in preference to any other text alternative.
-      if (this.hasAttribute('aria-label')) {
-        // Set `role` if it has not been overridden.
-        if (!this.hasAttribute('role')) {
-          this.setAttribute('role', 'img');
-        }
-        return;
-      }
-      this.updateAlt();
-    },
-
-    srcChanged: function() {
-      var icon = this._icon || document.createElement('div');
-      icon.textContent = '';
-      icon.setAttribute('fit', '');
-      icon.style.backgroundImage = 'url(' + this.src + ')';
-      icon.style.backgroundPosition = 'center';
-      icon.style.backgroundSize = '100%';
-      if (!icon.parentNode) {
-        this.appendChild(icon);
-      }
-      this._icon = icon;
-    },
-
-    getIconset: function(name) {
-      return meta.byId(name || this.defaultIconset);
-    },
-
-    updateIcon: function(oldVal, newVal) {
-      if (!this.icon) {
-        this.updateAlt();
-        return;
-      }
-      var parts = String(this.icon).split(':');
-      var icon = parts.pop();
-      if (icon) {
-        var set = this.getIconset(parts.pop());
-        if (set) {
-          this._icon = set.applyIcon(this, icon);
-          if (this._icon) {
-            this._icon.setAttribute('fit', '');
-          }
-        }
-      }
-      // Check to see if we're using the old icon's name for our a11y fallback
-      if (oldVal) {
-        if (oldVal.split(':').pop() == this.getAttribute('aria-label')) {
-          this.updateAlt();
-        }
-      }
-    },
-
-    updateAlt: function() {
-      // Respect the user's decision to remove this element from
-      // the a11y tree
-      if (this.getAttribute('aria-hidden')) {
-        return;
-      }
-
-      // Remove element from a11y tree if `alt` is empty, otherwise
-      // use `alt` as `aria-label`.
-      if (this.alt === '') {
-        this.setAttribute('aria-hidden', 'true');
-        if (this.hasAttribute('role')) {
-          this.removeAttribute('role');
-        }
-        if (this.hasAttribute('aria-label')) {
-          this.removeAttribute('aria-label');
-        }
-      } else {
-        this.setAttribute('aria-label', this.alt ||
-                                        this.icon.split(':').pop());
-        if (!this.hasAttribute('role')) {
-          this.setAttribute('role', 'img');
-        }
-        if (this.hasAttribute('aria-hidden')) {
-          this.removeAttribute('aria-hidden');
-        }
-      }
-    }
-
-  });
-  
-})();
-</script>
-
-</polymer-element>