Update shelf spacing in Chrome OS according to the MD specs

ash/system/toast/toast_manager_unittest.cc

Index: ash/system/toast/toast_manager_unittest.cc
diff --git a/ash/system/toast/toast_manager_unittest.cc b/ash/system/toast/toast_manager_unittest.cc
index 72641e410c40397eba3c10dddb2745e4a9e87d7a..0aa82e6373fe8e93074e73dd2a48d8ad59d0e5f7 100644
--- a/ash/system/toast/toast_manager_unittest.cc
+++ b/ash/system/toast/toast_manager_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "ash/common/shelf/shelf_constants.h"
 #include "ash/display/display_manager.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf.h"
@@ -206,7 +207,7 @@ TEST_F(ToastManagerTest, PositionWithAutoHiddenBottomShelf) {
 
   EXPECT_TRUE(toast_bounds.Intersects(shelf->user_work_area_bounds()));
   EXPECT_NEAR(root_bounds.CenterPoint().x(), toast_bounds.CenterPoint().x(), 1);
-  EXPECT_EQ(root_bounds.bottom() - ShelfLayoutManager::kAutoHideSize - 5,
+  EXPECT_EQ(root_bounds.bottom() - kShelfAutoHideSize - 5,
             toast_bounds.bottom());
 }