Revert "chromeos: Move files in //ash/common to //ash, part 3"

ash/common/session/session_state_observer.h

Index: ash/common/session/session_state_observer.h
diff --git a/ash/session/session_state_observer.h b/ash/common/session/session_state_observer.h
similarity index 87%
rename from ash/session/session_state_observer.h
rename to ash/common/session/session_state_observer.h
index 4ff2d26b93b18ce6090391f142a6e7e084022095..99bdb423e7693a715585965fbeec8b7a52a727b4 100644
--- a/ash/session/session_state_observer.h
+++ b/ash/common/session/session_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_SESSION_SESSION_STATE_OBSERVER_H_
-#define ASH_SESSION_SESSION_STATE_OBSERVER_H_
+#ifndef ASH_COMMON_SESSION_SESSION_STATE_OBSERVER_H_
+#define ASH_COMMON_SESSION_SESSION_STATE_OBSERVER_H_
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
@@ -42,4 +42,4 @@ class ASH_EXPORT ScopedSessionStateObserver {
 
 }  // namespace ash
 
-#endif  // ASH_SESSION_SESSION_STATE_OBSERVER_H_
+#endif  // ASH_COMMON_SESSION_SESSION_STATE_OBSERVER_H_