mash: Move //ash/system/date to //ash/common

ash/common/system/date/tray_date.h

Index: ash/common/system/date/tray_date.h
diff --git a/ash/system/date/tray_date.h b/ash/common/system/date/tray_date.h
similarity index 94%
rename from ash/system/date/tray_date.h
rename to ash/common/system/date/tray_date.h
index 23a792c4932192b10ace146c74d49c8668fb810d..e062faea4938f993fae75cd49350625673cd7f5d 100644
--- a/ash/system/date/tray_date.h
+++ b/ash/common/system/date/tray_date.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef ASH_SYSTEM_DATE_TRAY_DATE_H_
-#define ASH_SYSTEM_DATE_TRAY_DATE_H_
+#ifndef ASH_COMMON_SYSTEM_DATE_TRAY_DATE_H_
+#define ASH_COMMON_SYSTEM_DATE_TRAY_DATE_H_
 
 #include <memory>
 
@@ -83,4 +83,4 @@ class ASH_EXPORT TrayDate : public SystemTrayItem, public ClockObserver {
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_DATE_TRAY_DATE_H_
+#endif  // ASH_COMMON_SYSTEM_DATE_TRAY_DATE_H_