Start removing some pre-md constants and related code.

ash/common/system/tray/tray_details_view.h

 // Copyright (c) 2012 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.
 
 #ifndef ASH_COMMON_SYSTEM_TRAY_TRAY_DETAILS_VIEW_H_
 #define ASH_COMMON_SYSTEM_TRAY_TRAY_DETAILS_VIEW_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/system/tray/special_popup_row.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/view_click_listener.h"
 #include "base/macros.h"
-#include "grit/ash_strings.h"
+#include "base/timer/timer.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/view.h"
 
-namespace base {
-class OneShotTimer;
-}  // namespace base
-
 namespace views {
 class BoxLayout;
 class CustomButton;
 class ProgressBar;
 class ScrollView;
 }  // namespace views
 
 namespace ash {
 namespace test {
 class TrayDetailsViewTest;
@@ skipping 99 matching lines @@
 
   ScrollBorder* scroll_border_;  // Weak reference
 
   // The container view for the top-most title row in material design.
   TriView* tri_view_;
 
   // The back button that appears in the material design title row. Not owned.
   views::Button* back_button_;
 
   // Used to delay the transition to the default view.
-  std::unique_ptr<base::OneShotTimer> transition_delay_timer_;
+  base::OneShotTimer transition_delay_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayDetailsView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_DETAILS_VIEW_H_