Revert of chromeos: Move ownership of system tray width from chrome to ash

ash/common/system/tray/system_tray_delegate.h

Index: ash/common/system/tray/system_tray_delegate.h
diff --git a/ash/common/system/tray/system_tray_delegate.h b/ash/common/system/tray/system_tray_delegate.h
index 756888ef82ed2387d4872a82b017e0a0989415c5..bd492e9d6050510471f0c9b764a213b277103265 100644
--- a/ash/common/system/tray/system_tray_delegate.h
+++ b/ash/common/system/tray/system_tray_delegate.h
@@ -225,6 +225,9 @@
   // Retrieves the session length limit. Returns |false| if no limit is set.
   virtual bool GetSessionLengthLimit(base::TimeDelta* session_length_limit);
 
+  // Get the system tray menu size in pixels (dependent on the language).
+  virtual int GetSystemTrayMenuWidth();
+
   // The active user has been changed. This will be called when the UI is ready
   // to be switched to the new user.
   // Note: This will happen after SessionStateObserver::ActiveUserChanged fires.