[ash-md] Remove non-md code from the Shelf background animations.

ash/common/shelf/shelf_constants.h

Index: ash/common/shelf/shelf_constants.h
diff --git a/ash/common/shelf/shelf_constants.h b/ash/common/shelf/shelf_constants.h
index dc584ebff63c998b038bdcf81fcb741825be0e35..f875900a8c9facd8aebe500159d47a87286f6bc4 100644
--- a/ash/common/shelf/shelf_constants.h
+++ b/ash/common/shelf/shelf_constants.h
@@ -11,9 +11,6 @@
 namespace ash {
 
 enum ShelfConstant {
-  // The alpha value for the shelf background when a window is overlapping.
-  SHELF_BACKGROUND_ALPHA,
-
   // Size of the shelf when visible (height when the shelf is horizontal and
   // width when the shelf is vertical).
   SHELF_SIZE,
@@ -65,6 +62,9 @@ extern const float kShelfInkDropVisibleOpacity;
 // notifications, etc).
 ASH_EXPORT extern const SkColor kShelfIconColor;
 
+// The alpha value for the shelf background when a window is overlapping.
+ASH_EXPORT extern const int kShelfTranslucentAlpha;
+
 // The width and height of the material design overflow button.
 // TODO(tdanderson): Refactor constants which are common between the shelf
 // and the tray. See crbug.com/623987.