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

ash/system/chromeos/screen_layout_observer.h

Index: ash/system/chromeos/screen_layout_observer.h
diff --git a/ash/system/screen_layout_observer.h b/ash/system/chromeos/screen_layout_observer.h
similarity index 94%
rename from ash/system/screen_layout_observer.h
rename to ash/system/chromeos/screen_layout_observer.h
index 24943aeecc17e92f9555a3478ce1af1c46d0683d..1ef8bbb74fa3b1df0e34310216f992dfff4399b7 100644
--- a/ash/system/screen_layout_observer.h
+++ b/ash/system/chromeos/screen_layout_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_SCREEN_LAYOUT_OBSERVER_H_
-#define ASH_SYSTEM_SCREEN_LAYOUT_OBSERVER_H_
+#ifndef ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
+#define ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
 
 #include <stdint.h>
 
@@ -84,4 +84,4 @@ class ASH_EXPORT ScreenLayoutObserver : public WmDisplayObserver {
 
 }  // namespace ash
 
-#endif  // ASH_SYSTEM_SCREEN_LAYOUT_OBSERVER_H_
+#endif  // ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_