Mark supervised profiles as such immediately when they're created.

chrome/browser/ui/webui/downloads_ui_browsertest.h

Index: chrome/browser/ui/webui/downloads_ui_browsertest.h
diff --git a/chrome/browser/ui/webui/downloads_ui_browsertest.h b/chrome/browser/ui/webui/downloads_ui_browsertest.h
index f5370c839289827f40c438b3511b80a1c1add87b..d38ee1e9cbd7d43f08018233c82f8f090e2479bc 100644
--- a/chrome/browser/ui/webui/downloads_ui_browsertest.h
+++ b/chrome/browser/ui/webui/downloads_ui_browsertest.h
@@ -17,10 +17,14 @@ class DownloadsUIBrowserTest : public WebUIBrowserTest {
   // Sets the pref to allow or prohibit deleting history entries.
   void SetDeleteAllowed(bool allowed);
 
-  void ChangeProfileToSupervised();
-
  private:
   DISALLOW_COPY_AND_ASSIGN(DownloadsUIBrowserTest);
 };
 
+class DownloadsWebUIForSupervisedUsersTest : public DownloadsUIBrowserTest {
+ public:
+  // InProcessBrowserTest overrides:
+  virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE;
+};
+
 #endif  // CHROME_BROWSER_UI_WEBUI_DOWNLOADS_UI_BROWSERTEST_H_