ash uber tray: Add entry for power and date.

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 2413c4b2cf3a3fe9288f82a25ca593288d46fbb9..baaf2951e45dde85e20aa2c0785d0fd628e75944 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -43,6 +43,7 @@ class BrightnessController;
 class Launcher;
 class NestedDispatcherController;
 class PowerButtonController;
+class PowerStatusController;
 class ShellDelegate;
 class SystemTrayDelegate;
 class SystemTray;
@@ -198,6 +199,9 @@ class ASH_EXPORT Shell {
   BrightnessController* brightness_controller() const {
     return brightness_controller_;
   }
+  PowerStatusController* power_status_controller() const {
+    return power_status_controller_;
+  }
 
   ShellDelegate* delegate() { return delegate_.get(); }
   SystemTrayDelegate* tray_delegate() { return tray_delegate_.get(); }
@@ -282,9 +286,10 @@ class ASH_EXPORT Shell {
   scoped_ptr<WindowCycleController> window_cycle_controller_;
   scoped_ptr<internal::FocusCycler> focus_cycler_;
 
-  // The audio and brightness controllers are not owner by the shell.
+  // These controllers are not owner by the shell.
   AudioController* audio_controller_;
   BrightnessController* brightness_controller_;
+  PowerStatusController* power_status_controller_;
 
   // An event filter that pre-handles all key events to send them to an IME.
   scoped_ptr<internal::InputMethodEventFilter> input_method_filter_;