Implemented system tray UI for new account management.

ash/shell_delegate.h

Index: ash/shell_delegate.h
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index ba28e0ca26cf941c3737507dac9193f368272067..5ea1f254d53cc6ae717c7d2fe1a688d11a163fdd 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -72,6 +72,9 @@ class ASH_EXPORT ShellDelegate {
   // Returns true if we're running in forced app mode.
   virtual bool IsRunningInForcedAppMode() const = 0;
 
+  // Returns true if new account management is enabled.
+  virtual bool IsAccountManagementEnabled() const = 0;
+
   // Called before processing |Shell::Init()| so that the delegate
   // can perform tasks necessary before the shell is initialized.
   virtual void PreInit() = 0;