chromeos: Refactor ash SystemTrayDelegate enterprise methods to mojo

ash/system/tray/system_tray_delegate.cc

Index: ash/system/tray/system_tray_delegate.cc
diff --git a/ash/system/tray/system_tray_delegate.cc b/ash/system/tray/system_tray_delegate.cc
index 5fc51d9109881de17df17e6255f5bbc4eb94c4db..ef9087988b6ccec0cb3b8b2c4151669b1726b3c5 100644
--- a/ash/system/tray/system_tray_delegate.cc
+++ b/ash/system/tray/system_tray_delegate.cc
@@ -19,20 +19,6 @@ LoginStatus SystemTrayDelegate::GetUserLoginStatus() const {
   return LoginStatus::NOT_LOGGED_IN;
 }
 
-std::string SystemTrayDelegate::GetEnterpriseDomain() const {
-  return std::string();
-}
-
-std::string SystemTrayDelegate::GetEnterpriseRealm() const {
-  return std::string();
-}
-
-base::string16 SystemTrayDelegate::GetEnterpriseMessage() const {
-  return base::string16();
-}
-
-void SystemTrayDelegate::ShowEnterpriseInfo() {}
-
 void SystemTrayDelegate::ShowUserLogin() {}
 
 void SystemTrayDelegate::GetCurrentIME(IMEInfo* info) {}