ash uber tray: Add a tray item for the user.

ash/system/tray/system_tray_delegate.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 ASH_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 #define ASH_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 #pragma once
 
+class SkBitmap;
+
 namespace ash {
 
 class SystemTrayDelegate {
  public:
   virtual ~SystemTrayDelegate() {}
 
+  // Gets information about the logged in user.
+  virtual const std::string GetUserDisplayName() = 0;
+  virtual const std::string GetUserEmail() = 0;
+  virtual const SkBitmap& GetUserImage() = 0;
+
   // Shows settings.
   virtual void ShowSettings() = 0;
 
   // Shows help.
   virtual void ShowHelp() = 0;
 
   // Is the system audio muted?
   virtual bool IsAudioMuted() const = 0;
 
   // Mutes/Unmutes the audio system.
   virtual void SetAudioMuted(bool muted) = 0;
 
   // Gets the volume level.
   virtual float GetVolumeLevel() const = 0;
 
   // Sets the volume level.
   virtual void SetVolumeLevel(float level) = 0;
+
+  // Attempts to shut down the system.
+  virtual void ShutDown() = 0;
+
+  // Attempts to sign out the user.
+  virtual void SignOut() = 0;
+
+  // Attempts to lock the screen.
+  virtual void LockScreen() = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_