Update shelf spacing in Chrome OS according to the MD specs

ash/shelf/shelf_widget.cc

Index: ash/shelf/shelf_widget.cc
diff --git a/ash/shelf/shelf_widget.cc b/ash/shelf/shelf_widget.cc
index 216b0901d32855775fe45832886cfcc803346162..f454807c262d41703298ac54811d282dea6e6c4f 100644
--- a/ash/shelf/shelf_widget.cc
+++ b/ash/shelf/shelf_widget.cc
@@ -276,15 +276,13 @@ class ShelfWindowTargeter : public ::wm::EasyResizeWindowTargeter,
     if (new_state == SHELF_VISIBLE) {
       // Let clicks at the very top of the shelf through so windows can be
       // resized with the bottom-right corner and bottom edge.
-      mouse_insets = GetInsetsForAlignment(
-          ShelfLayoutManager::kWorkspaceAreaVisibleInset,
-          shelf_->GetAlignment());
+      mouse_insets = GetInsetsForAlignment(kWorkspaceAreaVisibleInset,
+                                           shelf_->GetAlignment());
     } else if (new_state == SHELF_AUTO_HIDE) {
       // Extend the touch hit target out a bit to allow users to drag shelf out
       // while hidden.
-      touch_insets = GetInsetsForAlignment(
-          -ShelfLayoutManager::kWorkspaceAreaAutoHideInset,
-          shelf_->GetAlignment());
+      touch_insets = GetInsetsForAlignment(-kWorkspaceAreaAutoHideInset,
+                                           shelf_->GetAlignment());
     }
 
     set_mouse_extend(mouse_insets);