Settings Overides -- warn user when extensions override their NTP.

chrome/browser/ui/views/frame/browser_view.cc

Index: chrome/browser/ui/views/frame/browser_view.cc
diff --git a/chrome/browser/ui/views/frame/browser_view.cc b/chrome/browser/ui/views/frame/browser_view.cc
index 335e08bd2b44f7bcf007d0023b408ca2e4059d05..ed3cdb19584c9bc4237c8565c3fb3928642c6ee3 100644
--- a/chrome/browser/ui/views/frame/browser_view.cc
+++ b/chrome/browser/ui/views/frame/browser_view.cc
@@ -82,6 +82,7 @@
 #include "chrome/browser/ui/views/profiles/avatar_menu_bubble_view.h"
 #include "chrome/browser/ui/views/profiles/avatar_menu_button.h"
 #include "chrome/browser/ui/views/profiles/profile_chooser_view.h"
+#include "chrome/browser/ui/views/settings_api_bubble_helper_views.h"
 #include "chrome/browser/ui/views/status_bubble_views.h"
 #include "chrome/browser/ui/views/tabs/browser_tab_strip_controller.h"
 #include "chrome/browser/ui/views/tabs/tab.h"
@@ -1439,6 +1440,9 @@ void BrowserView::TabInsertedAt(WebContents* contents,
     DCHECK(contents->GetView()->GetNativeView()->GetRootWindow());
   }
   web_contents_close_handler_->TabInserted();
+
+  if (foreground)
+    extensions::MaybeShowExtensionControlledNewTabPage(browser(), contents);
 }
 
 void BrowserView::TabDetachedAt(WebContents* contents, int index) {