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

chrome/browser/background/background_mode_manager.h

 // Copyright (c) 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_BACKGROUND_BACKGROUND_MODE_MANAGER_H_
 #define CHROME_BROWSER_BACKGROUND_BACKGROUND_MODE_MANAGER_H_
 
 #include <map>
 
 #include "base/gtest_prod_util.h"
@@ skipping 288 matching lines @@
   // Returns the number of background apps in the system (virtual to allow
   // overriding in unit tests).
   virtual int GetBackgroundAppCount() const;
 
   // Returns the number of background apps for a profile.
   virtual int GetBackgroundAppCountForProfile(Profile* const profile) const;
 
   // Returns true if we should be in background mode.
   bool ShouldBeInBackgroundMode() const;
 
+  // Finds the BackgroundModeData associated with the last active profile,
+  // if the profile isn't locked. Returns NULL otherwise.
+  BackgroundModeManager::BackgroundModeData*
+      GetBackgroundModeDataForLastProfile() const;
+
   // Reference to the profile info cache. It is used to update the background
   // app status of profiles when they open/close background apps.
   ProfileInfoCache* profile_cache_;
 
   // Registrars for managing our change observers.
   content::NotificationRegistrar registrar_;
   PrefChangeRegistrar pref_registrar_;
 
   // The profile-keyed data for this background mode manager. Keyed on profile.
   BackgroundModeInfoMap background_mode_data_;
@@ skipping 33 matching lines @@
   // Set to true when background mode is suspended.
   bool background_mode_suspended_;
 
   // Set to true when background mode is keeping Chrome alive.
   bool keeping_alive_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundModeManager);
 };
 
 #endif  // CHROME_BROWSER_BACKGROUND_BACKGROUND_MODE_MANAGER_H_