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

ash/system/session/logout_button_observer.h

Index: ash/system/session/logout_button_observer.h
diff --git a/ash/common/system/chromeos/session/logout_button_observer.h b/ash/system/session/logout_button_observer.h
similarity index 80%
rename from ash/common/system/chromeos/session/logout_button_observer.h
rename to ash/system/session/logout_button_observer.h
index c0e7ce38f845773fcd4c55eac8109d1c7e959139..3e20cecf0242b7bd83b2c1943dbdb59a631c1276 100644
--- a/ash/common/system/chromeos/session/logout_button_observer.h
+++ b/ash/system/session/logout_button_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_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_OBSERVER_H_
-#define ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_OBSERVER_H_
+#ifndef ASH_SYSTEM_SESSION_LOGOUT_BUTTON_OBSERVER_H_
+#define ASH_SYSTEM_SESSION_LOGOUT_BUTTON_OBSERVER_H_
 
 #include "ash/ash_export.h"
 #include "base/time/time.h"
@@ -27,4 +27,4 @@ class ASH_EXPORT LogoutButtonObserver {
 
 }  // namespace ash
 
-#endif  // ASH_COMMON_SYSTEM_CHROMEOS_SESSION_LOGOUT_BUTTON_OBSERVER_H_
+#endif  // ASH_SYSTEM_SESSION_LOGOUT_BUTTON_OBSERVER_H_