Slightly nicer icon.js APIs.

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');

[michaelpg, 2016/09/02 20:00:38]

unfamiliar with ios and goog/Closure, so just a question: was this for cr.icon.*
or chrome.send('webui.requestFavicon', ...)?

I ask because presumably something somewhere is including icon.js that no longer
needs to include it, if this follows IWYU.

[Peter Kasting, 2016/09/02 20:21:42]

(For posterity, we discussed this offline and concluded that no changes are
needed)

 
 /**
  * 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 = cr.icon.getSupportedScaleFactors()[0];
+    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);
   }
 };