Bring up the Fast User Switcher on Shift+Click on the new Avatar Button

chrome/browser/ui/browser_window.h

 // Copyright 2012 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_BROWSER_WINDOW_H_
 #define CHROME_BROWSER_UI_BROWSER_WINDOW_H_
 
 #include "base/callback_forward.h"
 #include "chrome/browser/lifetime/browser_close_manager.h"
 #include "chrome/browser/signin/signin_header_helper.h"
@@ skipping 363 matching lines @@
   // Shows the avatar bubble on the window frame off of the avatar button with
   // the given mode. The Service Type specified by GAIA is provided as well.
   enum AvatarBubbleMode {
     AVATAR_BUBBLE_MODE_DEFAULT,
     AVATAR_BUBBLE_MODE_ACCOUNT_MANAGEMENT,
     AVATAR_BUBBLE_MODE_SIGNIN,
     AVATAR_BUBBLE_MODE_ADD_ACCOUNT,
     AVATAR_BUBBLE_MODE_REAUTH,
     AVATAR_BUBBLE_MODE_CONFIRM_SIGNIN,
     AVATAR_BUBBLE_MODE_SHOW_ERROR,
+    AVATAR_BUBBLE_MODE_FAST_USER_SWITCH,
   };
   virtual void ShowAvatarBubbleFromAvatarButton(AvatarBubbleMode mode,
       const signin::ManageAccountsParams& manage_accounts_params) = 0;
 
   // Returns the height inset for RenderView when detached bookmark bar is
   // shown.  Invoked when a new RenderHostView is created for a non-NTP
   // navigation entry and the bookmark bar is detached.
   virtual int GetRenderViewHeightInsetWithDetachedBookmarkBar() = 0;
 
   // Executes |command| registered by |extension|.
   virtual void ExecuteExtensionCommand(const extensions::Extension* extension,
                                        const extensions::Command& command) = 0;
 
  protected:
   friend class BrowserCloseManager;
   friend class BrowserView;
   virtual void DestroyBrowser() = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_BROWSER_WINDOW_H_