MD Settings: Ignore whitespace only search queries.

chrome/test/data/webui/settings/settings_ui_browsertest.js

Index: chrome/test/data/webui/settings/settings_ui_browsertest.js
diff --git a/chrome/test/data/webui/settings/settings_ui_browsertest.js b/chrome/test/data/webui/settings/settings_ui_browsertest.js
index 23670621c3010791ec7ed086e662f2162866ee40..980a028e97f9cbb796ecaf4b51b99418c79cbb45 100644
--- a/chrome/test/data/webui/settings/settings_ui_browsertest.js
+++ b/chrome/test/data/webui/settings/settings_ui_browsertest.js
@@ -125,6 +125,16 @@ TEST_F('SettingsUIBrowserTest', 'MAYBE_All', function() {
       settings.navigateTo(settings.Route.BASIC);
       assertEquals('', searchField.getSearchInput().bindValue);
     });
+
+    test('whitespace only search query is ignored', function() {
+      toolbar = /** @type {!CrToolbarElement} */ (ui.$$('cr-toolbar'));
+      var searchField = /** @type {CrToolbarSearchFieldElement} */ (
+          toolbar.getSearchField());
+      searchField.setValue('    ');
+
+      var urlParams = settings.getQueryParameters();
+      assertFalse(urlParams.has('search'));
+    });
   });
 
   mocha.run();