Remove WebUI favicon support on iOS

ios/web/webui/resources/web_ui_favicons.js

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file adheres to closure-compiler conventions in order to enable
-// compilation with ADVANCED_OPTIMIZATIONS. In particular, members that are to
-// be accessed externally should be specified in this['style'] as opposed to
-// this.style because member identifiers are minified by default.
-// See http://goo.gl/FwOgy
-
-goog.require('__crWeb.webUIBase');
-
-goog.provide('__crWeb.webUIFavicons');
-
-/**
- * Sends message requesting favicon at the URL from imageSet for el. Sets
- * favicon-url attribute on el to the favicon URL.
- * @param {Element} el The DOM element to request the favicon for.
- * @param {string} imageSet The CSS -webkit-image-set.
- */
-window['chrome']['requestFavicon'] = function(el, imageSet) {
-  var cssUrls = imageSet.match(/url\([^\)]+\) \dx/g);
-  // TODO(jyquinn): Review match above (crbug.com/528080).
-  if (!cssUrls) {
-    return;
-  }
-  // Extract url from CSS -webkit-image-set.
-  var faviconUrl = '';
-  for (var i = 0; i < cssUrls.length; ++i) {
-    var scaleFactorExp = /(\d)x$/;
-    var scaleFactor = window.devicePixelRatio;
-    if (parseInt(scaleFactorExp.exec(cssUrls[i])[1], 10) === scaleFactor) {
-      var urlExp = /url\(\"(.+)\"\)/;
-      faviconUrl = urlExp.exec(cssUrls[i])[1];
-      break;
-    }
-  }
-  el.setAttribute('favicon-url', url(faviconUrl));
-  chrome.send('webui.requestFavicon', [faviconUrl]);
-};
-
-/**
- * Called to set elements with favicon-url attribute equal to faviconUrl to
- * provided dataUrl.
- * @param {string} faviconUrl Favicon URL used to locate favicon element
- *     via the favicon-url attribute.
- * @param {string} dataUrl The data URL to assign to the favicon element's
- *    backgroundImage.
- */
-window['chrome']['setFaviconBackground'] = function(faviconUrl, dataUrl) {
-  var selector = "[favicon-url='" + url(faviconUrl) + "']";
-  var elements = document.querySelectorAll(selector);
-  for (var i = 0; i < elements.length; ++i) {
-    elements[i].style.backgroundImage = url(dataUrl);
-  }
-};