Clean up some ash constants.

ash/shelf/shelf_constants.h

Index: ash/shelf/shelf_constants.h
diff --git a/ash/shelf/shelf_constants.h b/ash/shelf/shelf_constants.h
index 65662ec399c6ca6440f0ebf064baa3c5417ed267..807493751c6dbae790b04f05c5b4ae93bbbdf120 100644
--- a/ash/shelf/shelf_constants.h
+++ b/ash/shelf/shelf_constants.h
@@ -10,14 +10,9 @@
 
 namespace ash {
 
-enum ShelfConstant {
-  // Size of the shelf when visible (height when the shelf is horizontal and
-  // width when the shelf is vertical).
-  SHELF_SIZE,
-
-  // Insets allocated for shelf when it is auto hidden.
-  SHELF_INSETS_FOR_AUTO_HIDE
-};
+// Size of the shelf when visible (height when the shelf is horizontal and
+// width when the shelf is vertical).
+ASH_EXPORT constexpr int kShelfSize = 48;
 
 // We reserve a small area on the edge of the workspace area to ensure that
 // the resize handle at the edge of the window can be hit.
@@ -83,8 +78,6 @@ constexpr int kAppListButtonRadius = kOverflowButtonSize / 2;
 // The direction of the focus cycling.
 enum CycleDirection { CYCLE_FORWARD, CYCLE_BACKWARD };
 
-ASH_EXPORT int GetShelfConstant(ShelfConstant shelf_constant);
-
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_CONSTANTS_H_