Settings Router Refactor: Remove route.page legacy property.

chrome/browser/resources/settings/settings_page/main_page_behavior.js

 // Copyright 2016 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.
 
 // Fast out, slow in.
 var EASING_FUNCTION = 'cubic-bezier(0.4, 0, 0.2, 1)';
 var EXPAND_DURATION = 350;
 
 /**
  * Calls |readyTest| repeatedly until it returns true, then calls
@@ skipping 389 matching lines @@
         if (section)
           this.expandSection(section);
       }
     } else {
       if (oldRouteIsSubpage) {
         var section = this.getSection_(oldRoute.section);
         if (section)
           this.collapseSection(section);
       }
 
-      if (newRoute && newRoute.section &&
-          this.$$('[data-page=' + newRoute.page + ']')) {
+      // Scrolls to the section if this main page contains the route's section.
+      if (newRoute && newRoute.section && this.getSection_(newRoute.section))
         this.scrollToSection_();
-      }
     }
   },
 
   /**
    * Helper function to get a section from the local DOM.
    * @param {string} section Section name of the element to get.
    * @return {?SettingsSectionElement}
    * @private
    */
   getSection_: function(section) {
     return /** @type {?SettingsSectionElement} */(
         this.$$('[section=' + section + ']'));
   },
 };
 
 
 /** @polymerBehavior */
 var RoutableBehavior = [
   MainPageBehavior,
   RoutableBehaviorImpl
 ];