mash: Migrate tray date view to //ash/common types

ash/common/system/tray/system_tray_delegate.cc

Index: ash/common/system/tray/system_tray_delegate.cc
diff --git a/ash/common/system/tray/system_tray_delegate.cc b/ash/common/system/tray/system_tray_delegate.cc
index 465c5357e3786a2913ede0ec6ee00c102a2947d1..3f18b1f38b3b41a944e3dcb15f5cf841c5216bce 100644
--- a/ash/common/system/tray/system_tray_delegate.cc
+++ b/ash/common/system/tray/system_tray_delegate.cc
@@ -168,6 +168,8 @@ void SystemTrayDelegate::RequestLockScreen() {
 void SystemTrayDelegate::RequestRestartForUpdate() {
 }
 
+void SystemTrayDelegate::RequestShutdown() {}
+
 void SystemTrayDelegate::GetAvailableBluetoothDevices(
     BluetoothDeviceList* list) {
 }