Settings Router Refactor: Kill settings-router.

chrome/browser/resources/settings/route.js

Index: chrome/browser/resources/settings/route.js
diff --git a/chrome/browser/resources/settings/route.js b/chrome/browser/resources/settings/route.js
index 728caf47cb9af00d15b0dc0c7c50bc95b371b62f..096b3c13c9ecc79ea540eec75d273a1504609128 100644
--- a/chrome/browser/resources/settings/route.js
+++ b/chrome/browser/resources/settings/route.js
@@ -270,6 +270,10 @@ cr.define('settings', function() {
     attached: function() {
       assert(!routeObservers_.has(this));
       routeObservers_.add(this);
+
+      // Emulating Polymer data bindings, the observer is called when the
+      // element starts observing the route.
+      this.currentRouteChanged(currentRoute_, undefined);
     },
 
     /** @override */
@@ -325,10 +329,11 @@ cr.define('settings', function() {
    * @param {!URLSearchParams} queryParameters
    */
   var setCurrentRoute = function(route, queryParameters) {
+    var oldRoute = currentRoute_;
     currentRoute_ = route;
     currentQueryParameters_ = queryParameters;
     for (var observer of routeObservers_)
-      observer.currentRouteChanged();
+      observer.currentRouteChanged(currentRoute_, oldRoute);
   };
 
   /** @return {!settings.Route} */