Remove importHref from 3.0

Author: kevinpschaaf

lib/legacy/legacy-element-mixin.js

@@ -13,7 +13,6 @@ import { ElementMixin } from '../mixins/element-mixin.js';
 import { GestureEventListeners } from '../mixins/gesture-event-listeners.js';
 import { DirMixin } from '../mixins/dir-mixin.js';
 import { dedupingMixin } from '../utils/mixin.js';
-import { importHref as importHref$0 } from '../utils/import-href.js';
 import '../utils/render-status.js';
 import '../utils/unresolved.js';
 import { dom as dom$0, matchesSelector } from './polymer.dom.js';
@@ -798,29 +797,6 @@ export const LegacyElementMixin = dedupingMixin((base) => {
       return elt;
     }
 
-    /**
-     * Convenience method for importing an HTML document imperatively.
-     *
-     * This method creates a new `<link rel="import">` element with
-     * the provided URL and appends it to the document to start loading.
-     * In the `onload` callback, the `import` property of the `link`
-     * element will contain the imported document contents.
-     *
-     * @param {string} href URL to document to load.
-     * @param {?function(!Event):void=} onload Callback to notify when an import successfully
-     *   loaded.
-     * @param {?function(!ErrorEvent):void=} onerror Callback to notify when an import
-     *   unsuccessfully loaded.
-     * @param {boolean=} optAsync True if the import should be loaded `async`.
-     *   Defaults to `false`.
-     * @return {!HTMLLinkElement} The link element for the URL to be loaded.
-     */
-    importHref(href, onload, onerror, optAsync) { // eslint-disable-line no-unused-vars
-      let loadFn = onload ? onload.bind(this) : null;
-      let errorFn = onerror ? onerror.bind(this) : null;
-      return importHref$0(href, loadFn, errorFn, optAsync);
-    }
-
     /**
      * Polyfill for Element.prototype.matches, which is sometimes still
      * prefixed.