MD Settings: Preserve search URL param in subpages.

chrome/test/data/webui/settings/route_tests.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.
 
 suite('route', function() {
   /**
    * Returns a new promise that resolves after a window 'popstate' event.
    * @return {!Promise}
    */
   function whenPopState(causeEvent) {
@@ skipping 108 matching lines @@
     assertEquals(settings.Route.BASIC, settings.getCurrentRoute());
   });
 
   test('navigate back to BASIC when going back from root pages', function() {
     settings.navigateTo(settings.Route.PEOPLE);
     settings.navigateTo(settings.Route.ADVANCED);
     settings.navigateToPreviousRoute();
     assertEquals(settings.Route.BASIC, settings.getCurrentRoute());
   });
 
+  test('navigateTo respects removeSearch optional parameter', function() {
+    var params = new URLSearchParams('search=foo');
+    settings.navigateTo(settings.Route.BASIC, params);
+    assertEquals(params.toString(), settings.getQueryParameters().toString());
+
+    settings.navigateTo(
+        settings.Route.SITE_SETTINGS, null, /* removeSearch */ false);
+    assertEquals(params.toString(), settings.getQueryParameters().toString());
+
+    settings.navigateTo(
+        settings.Route.SEARCH_ENGINES, null, /* removeSearch */ true);
+    assertEquals('', settings.getQueryParameters().toString());
+  });
+
   test('popstate flag works', function() {
     settings.navigateTo(settings.Route.BASIC);
     assertFalse(settings.lastRouteChangeWasPopstate());
 
     settings.navigateTo(settings.Route.PEOPLE);
     assertFalse(settings.lastRouteChangeWasPopstate());
 
     return whenPopState(function() {
       window.history.back();
     }).then(function() {
       assertEquals(settings.Route.BASIC, settings.getCurrentRoute());
       assertTrue(settings.lastRouteChangeWasPopstate());
 
       settings.navigateTo(settings.Route.ADVANCED);
       assertFalse(settings.lastRouteChangeWasPopstate());
     });
   });
 });