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

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

Index: ash/common/system/chromeos/network/network_observer.h
diff --git a/ash/system/network/network_observer.h b/ash/common/system/chromeos/network/network_observer.h
similarity index 72%
rename from ash/system/network/network_observer.h
rename to ash/common/system/chromeos/network/network_observer.h
index b548f71e8eb629ae3822382072b5b5a27d0e419b..3cf668ff09bad84d3060fe7192cd3691724cf2a6 100644
--- a/ash/system/network/network_observer.h
+++ b/ash/common/system/chromeos/network/network_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_NETWORK_OBSERVER_H_
-#define ASH_SYSTEM_NETWORK_NETWORK_OBSERVER_H_
+#ifndef ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_OBSERVER_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_OBSERVER_H_
 
 namespace ash {
 
@@ -19,4 +19,4 @@ class NetworkObserver {
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_NETWORK_NETWORK_OBSERVER_H_
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_NETWORK_NETWORK_OBSERVER_H_