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

chrome/browser/browser_about_handler.cc

Index: chrome/browser/browser_about_handler.cc
diff --git a/chrome/browser/browser_about_handler.cc b/chrome/browser/browser_about_handler.cc
index 04274b19630444720285912579e02d40cfcc37a8..8b449511819c3b10d8fc04e1c95ff8cbec6ab45d 100644
--- a/chrome/browser/browser_about_handler.cc
+++ b/chrome/browser/browser_about_handler.cc
@@ -88,20 +88,23 @@ bool WillHandleBrowserAboutURL(GURL* url,
       path = chrome::kChromeUIHistoryHost + url->path();
 #endif
     }
-  // Redirect chrome://settings
+    // Redirect chrome://settings, unless MD settings is enabled.
   } else if (host == chrome::kChromeUISettingsHost) {
     if (::switches::AboutInSettingsEnabled()) {
       host = chrome::kChromeUISettingsFrameHost;
-    } else {
+    } else if (!base::FeatureList::IsEnabled(
+                   features::kMaterialDesignSettingsFeature)) {
       host = chrome::kChromeUIUberHost;
       path = chrome::kChromeUISettingsHost + url->path();
     }
-  // Redirect chrome://help
+    // Redirect chrome://help, unless MD settings is enabled.
   } else if (host == chrome::kChromeUIHelpHost) {
     if (::switches::AboutInSettingsEnabled()) {
       host = chrome::kChromeUISettingsFrameHost;
       if (url->path().empty() || url->path() == "/")
         path = chrome::kChromeUIHelpHost;
+    } else if (!base::FeatureList::IsEnabled(
+                   features::kMaterialDesignSettingsFeature)) {
     } else {

[Dan Beam, 2016/06/03 03:01:43]

this } else { seems wrong

[groby-ooo-7-16, 2016/06/06 20:11:59]

Sure does. Thanks for catching.

       host = chrome::kChromeUIUberHost;
       path = chrome::kChromeUIHelpHost + url->path();