[MD Settings] Add feature to enable md-settings by default.

chrome/browser/ui/webui/uber/uber_ui_browsertest.cc

Index: chrome/browser/ui/webui/uber/uber_ui_browsertest.cc
diff --git a/chrome/browser/ui/webui/uber/uber_ui_browsertest.cc b/chrome/browser/ui/webui/uber/uber_ui_browsertest.cc
index 8c1862c12d46e13d6141453aaebad694bce1447f..19e7a326e930cf060632f09dee18a30d5b3cb6f0 100644
--- a/chrome/browser/ui/webui/uber/uber_ui_browsertest.cc
+++ b/chrome/browser/ui/webui/uber/uber_ui_browsertest.cc
@@ -105,6 +105,18 @@ IN_PROC_BROWSER_TEST_F(UberUIBrowserTest, EnableMdHistoryHidesHistory) {
   EXPECT_TRUE(GetJsBool("$('history').hidden"));
 }
 
+IN_PROC_BROWSER_TEST_F(UberUIBrowserTest, EnableMdSettingsHidesSettings) {
+  std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->InitializeFromCommandLine(
+      features::kMaterialDesignSettingsFeature.name, "");
+  base::FeatureList::ClearInstanceForTesting();
+  base::FeatureList::SetInstance(std::move(feature_list));
+
+  ui_test_utils::NavigateToURL(browser(), GURL(chrome::kChromeUIUberFrameURL));
+  SelectTab();
+  EXPECT_TRUE(GetJsBool("$('settings').hidden && $('help').hidden"));
+}
+
 IN_PROC_BROWSER_TEST_F(UberUIBrowserTest,
                        EnableSettingsWindowHidesSettingsAndHelp) {
   base::CommandLine::ForCurrentProcess()->AppendSwitch(