Clean up a few more unused globals.

ui/app_list/cocoa/item_drag_controller.mm

Index: ui/app_list/cocoa/item_drag_controller.mm
diff --git a/ui/app_list/cocoa/item_drag_controller.mm b/ui/app_list/cocoa/item_drag_controller.mm
index a4413c0b4d26d54a0ab8c4d86221fbe2119e0216..1de425b97d5a2dfc3d3af94752fee2fa15a0c6bd 100644
--- a/ui/app_list/cocoa/item_drag_controller.mm
+++ b/ui/app_list/cocoa/item_drag_controller.mm
@@ -8,17 +8,13 @@
 #import "ui/app_list/cocoa/apps_grid_view_item.h"
 #include "ui/base/cocoa/window_size_constants.h"
 
-namespace {
-
 // Scale to transform the grid cell when a drag starts. Note that 1.5 ensures
 // that integers are used for the layer bounds when the grid cell dimensions
 // are even.
 const CGFloat kDraggingIconScale = 1.5;
 
 const NSTimeInterval kAnimationDuration = 0.2;
-NSString* const kGrowAnimationKey = @"growAnimation";
 
-}  // namespace
 
 @interface ItemDragController ()