Revert "chromeos: Move files in //ash/common to //ash, part 1"

ash/common/system/chromeos/network/tray_network_state_observer.h

Index: ash/common/system/chromeos/network/tray_network_state_observer.h
diff --git a/ash/system/network/tray_network_state_observer.h b/ash/common/system/chromeos/network/tray_network_state_observer.h
similarity index 88%
rename from ash/system/network/tray_network_state_observer.h
rename to ash/common/system/chromeos/network/tray_network_state_observer.h
index 9e6e8ed3ac74713a9f10704ee0f8623a74b880c3..178a68095e4e02e2b176bb7521f0dbbba84062de 100644
--- a/ash/system/network/tray_network_state_observer.h
+++ b/ash/common/system/chromeos/network/tray_network_state_observer.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_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_
-#define ASH_SYSTEM_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_
+#ifndef ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_
 
 #include "base/macros.h"
 #include "base/timer/timer.h"
@@ -58,4 +58,4 @@ class TrayNetworkStateObserver : public chromeos::NetworkStateHandlerObserver {
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_TRAY_NETWORK_STATE_OBSERVER_H_