Access to Chrome via the System Tray should go through the User Manager.

chrome/browser/ui/views/profiles/user_manager_view.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_PROFILES_USER_MANAGER_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_PROFILES_USER_MANAGER_VIEW_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_window.h"
 #include "ui/views/window/dialog_delegate.h"
 
 class AutoKeepAlive;
 
 namespace views {
 class WebView;
 }
 
 // Dialog widget that contains the Desktop User Manager webui.
 class UserManagerView : public views::DialogDelegateView {
  public:
   // Shows the User Manager or re-activates an existing one, focusing the
   // profile given by |profile_path_to_focus|. Based on the value of
   // |tutorial_mode|, a tutorial could be shown, in which case
-  // |profile_path_to_focus| is ignored.
+  // |profile_path_to_focus| is ignored. After a profile is opened, execute the
+  // |profile_open_action|.
   static void Show(const base::FilePath& profile_path_to_focus,
-                   profiles::UserManagerTutorialMode tutorial_mode);
+                   profiles::UserManagerTutorialMode tutorial_mode,
+                   profiles::UserManagerProfileSelected profile_open_action);
 
   // Hide the User Manager.
   static void Hide();
 
   // Returns whether or not the User Manager is showing.
   static bool IsShowing();
 
  private:
   friend struct base::DefaultDeleter<UserManagerView>;
 
@@ skipping 28 matching lines @@
 
   scoped_ptr<AutoKeepAlive> keep_alive_;
   // An open User Manager window. There can only be one open at a time. This
   // is reset to NULL when the window is closed.
   static UserManagerView* instance_;
 
   DISALLOW_COPY_AND_ASSIGN(UserManagerView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PROFILES_USER_MANAGER_VIEW_H_