Update shelf spacing in Chrome OS according to the MD specs

ash/system/toast/toast_manager_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // 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"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
 #include "ash/system/toast/toast_manager.h"
 #include "ash/test/ash_test_base.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "ui/compositor/scoped_animation_duration_scale_mode.h"
@@ skipping 184 matching lines @@
 
   ShowToast("DUMMY", ToastData::kInfiniteDuration);
   EXPECT_EQ(1, GetToastSerial());
 
   gfx::Rect toast_bounds = GetCurrentWidget()->GetWindowBoundsInScreen();
   gfx::Rect root_bounds =
       ScreenUtil::GetShelfDisplayBoundsInRoot(Shell::GetPrimaryRootWindow());
 
   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());
 }
 
 TEST_F(ToastManagerTest, PositionWithHiddenBottomShelf) {
   ShelfLayoutManager* shelf =
       Shelf::ForPrimaryDisplay()->shelf_layout_manager();
   SetShelfAutoHideBehavior(SHELF_AUTO_HIDE_ALWAYS_HIDDEN);
   SetShelfAlignment(SHELF_ALIGNMENT_BOTTOM);
   SetShelfState(ash::SHELF_HIDDEN);
 
@@ skipping 88 matching lines @@
   EXPECT_EQ("TEXT3", GetCurrentText());
   // Cancel the shown toast.
   CancelToast(id3);
   // Confirm that the shown toast disappears.
   EXPECT_FALSE(GetCurrentOverlay());
   // Confirm that only 1 toast is shown.
   EXPECT_EQ(2, GetToastSerial());
 }
 
 }  // namespace ash