Replace enhanced bookmarks salient images with favicons

components/resources/enhanced_bookmarks/get_salient_image_url.js

-// Copyright 2015 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.
-
-goog.require('image.collections.extension.domextractor.DocumentImageExtractor');
-
-/*
- * Examines the DOM to find the image that is the most representative of the
- * webpage.
- */
-var GetSalientImageUrl = function() {
-  // Extract the referrer policy from the page.
-  var referrerPolicy = 'default';
-  var metaTags = document.getElementsByTagName('meta');
-  for (var i = 0; i < metaTags.length; i++) {
-    if (metaTags[i].name.toLowerCase() == 'referrer') {
-      referrerPolicy = metaTags[i].content.toLowerCase();
-      break;
-    }
-  }
-
-  // Determine which JSON method (stringify or encode) to use for encoding.
-  // Some pages use a library that overrides JSON, so JSON['stringify'] is not
-  // always available.
-  var jsonEncoder = JSON['stringify'];
-  if (!jsonEncoder)
-    jsonEncoder = JSON['encode'];
-
-  var context = new
-      image.collections.extension.domextractor.DocumentImageExtractor.Context();
-  var documentImageExtractor =
-      new image.collections.extension.domextractor.DocumentImageExtractor();
-  var images = documentImageExtractor.extractFromNodeList(
-      document.querySelectorAll('img,link,meta'), context);
-
-  var maxImage = null;
-  var maxRelevance = 0;
-  for (var i = 0; i < images.length; i++) {
-    var currentImage = images[i];
-    var imageSize = currentImage.getSize();
-    if (!imageSize)
-      continue;
-
-    if (currentImage.getRelevance() > maxRelevance) {
-      maxImage = currentImage;
-      maxRelevance = currentImage.getRelevance();
-    }
-  }
-
-  if (maxImage === null)
-    return '';
-
-  var result = jsonEncoder({
-    'imageUrl': maxImage.getUrl(),
-    'referrerPolicy': referrerPolicy
-  });
-
-  return result;
-};