MD Settings: Move browserProxies outside of Polymer "properties".

chrome/browser/resources/settings/appearance_page/appearance_fonts_page.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.
 
 (function() {
   'use strict';
 
   /**
    * This is the absolute difference maintained between standard and
    * fixed-width font sizes. http://crbug.com/91922.
@@ skipping 29 matching lines @@
     properties: {
       /** @private */
       advancedExtensionInstalled_: Boolean,
 
       /** @private */
       advancedExtensionSublabel_: String,
 
       /** @private */
       advancedExtensionUrl_: String,
 
-      /** @private {!settings.FontsBrowserProxy} */
-      browserProxy_: Object,
-
       /** @private {!DropdownMenuOptionList} */
       fontOptions_: Object,
 
       /** @private */
       isGuest_: {
         type: Boolean,
         value: function() { return loadTimeData.getBoolean('isGuest'); }
       },
 
       /**
@@ skipping 22 matching lines @@
       prefs: {
         type: Object,
         notify: true,
       },
     },
 
     observers: [
       'fontSizeChanged_(prefs.webkit.webprefs.default_font_size.value)',
     ],
 
+    /** @private {?settings.FontsBrowserProxy} */
+    browserProxy_: null,
+
     /** @override */
     created: function() {
       this.browserProxy_ = settings.FontsBrowserProxyImpl.getInstance();
     },
 
     /** @override */
     ready: function() {
       this.addWebUIListener('advanced-font-settings-installed',
           this.setAdvancedExtensionInstalled_.bind(this));
       this.browserProxy_.observeAdvancedFontExtensionAvailable();
@@ skipping 54 matching lines @@
      * Get the minimum font size, accounting for unset prefs.
      * @return {?}
      * @private
      */
     computeMinimumFontSize_: function() {
       return this.get('prefs.webkit.webprefs.minimum_font_size.value') ||
           MINIMUM_FONT_SIZE_RANGE_[0];
     },
   });
 })();