MD Settings: Preserve search URL param in subpages.

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 d90cbfa73d0ce6e46f40839ac27f1b11fcea9df4..8e57c76b9c91fba9365b11342aebdd75df2d6851 100644
--- a/chrome/browser/resources/settings/route.js
+++ b/chrome/browser/resources/settings/route.js
@@ -320,8 +320,12 @@ cr.define('settings', function() {
    * @param {URLSearchParams=} opt_dynamicParameters Navigations to the same
    *     search parameters in a different order will still push to history.
    */
-  var navigateTo = function(route, opt_dynamicParameters) {
+  var navigateTo = function(route, opt_dynamicParameters, opt_preserveSearch) {
+    var currentParams = getQueryParameters();
+    var oldSearchParam = currentParams.get('search') || '';
+
     var params = opt_dynamicParameters || new URLSearchParams();
+    var newSearchParam = params.get('search') || '';
 
     var url = route.path;
     if (opt_dynamicParameters) {
@@ -330,6 +334,14 @@ cr.define('settings', function() {
         url += '?' + queryString;
     }
 
+    var preserveSearch = opt_preserveSearch == undefined ?
+        true : !!opt_preserveSearch;
+    if (preserveSearch && oldSearchParam.length > 0 &&
+        newSearchParam.length == 0) {
+      url += '?' + `search=${oldSearchParam}`;
+      params.append('search', oldSearchParam);
+    }
+

[tommycli, 2016/11/03 23:31:33]

I would recommend doing something like this on line 329:

if (preserveSearch && oldSearchParam && !newSearchParam)
  params.append('search', oldSearchParam)

I think then the URL will be taken care of by 334 automatically, and you don't
need this block.

[dpapad, 2016/11/04 02:00:33]

Done. I also removed the "if (opt_dynamicParameters) {" check completely. 

     // History serializes the state, so we don't push the actual route object.
     window.history.pushState(currentRoute_.path, '', url);
     setCurrentRoute(route, params, false);