Use a correct scale factor for Gaia avatar images

ui/webui/resources/js/util.js

Index: ui/webui/resources/js/util.js
diff --git a/ui/webui/resources/js/util.js b/ui/webui/resources/js/util.js
index ebcf90c12d5adae6ae4a0cd98df9e1d2abca9d1e..56e2d2d283c0334f0dd4c6dd5f31bf0957deb38d 100644
--- a/ui/webui/resources/js/util.js
+++ b/ui/webui/resources/js/util.js
@@ -75,6 +75,21 @@ function url(s) {
 }
 
 /**
+ * Returns the URL of the image, or an image set of URLs for the profile avatar.
+ * Default avatars have resources available for multiple scalefactors, whereas
+ * the GAIA profile image only comes in one size.
+
+ * @param {string} url The path of the image.
+ * @return {string} The url, or an image set of URLs of the avatar image.
+ */
+function getProfileAvatarIcon(path) {
+  var chromeThemePath = 'chrome://theme';
+  var isDefaultAvatar =
+      (path.slice(0, chromeThemePath.length) == chromeThemePath);
+  return isDefaultAvatar ? imageset(path + '@scalefactorx'): url(path);
+}
+
+/**
  * Generates a CSS -webkit-image-set for a chrome:// url.
  * An entry in the image set is added for each of getSupportedScaleFactors().
  * The scale-factor-specific url is generated by replacing the first instance of