Template methods on Timer classes instead of the classes themselves.

ash/system/tray_update.cc

 // 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.
 
 #include "ash/system/tray_update.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
@@ skipping 132 matching lines @@
     else if (!timer_.IsRunning())
       RestartTimer();
   }
 
   void OnLayerAnimationAborted(ui::LayerAnimationSequence* sequence) override {}
 
   void OnLayerAnimationScheduled(
       ui::LayerAnimationSequence* sequence) override {}
 
   SystemTrayItem* owner_;
-  base::OneShotTimer<UpdateNagger> timer_;
+  base::OneShotTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateNagger);
 };
 
 }  // namespace tray
 
 TrayUpdate::TrayUpdate(SystemTray* system_tray)
     : TrayImageItem(system_tray, IDR_AURA_UBER_TRAY_UPDATE) {
   Shell::GetInstance()->system_tray_notifier()->AddUpdateObserver(this);
 }
@@ skipping 32 matching lines @@
   SetImageFromResourceId(DecideResource(info.severity, false));
   tray_view()->SetVisible(true);
   if (!Shell::GetPrimaryRootWindowController()->shelf()->IsVisible() &&
       !nagger_.get()) {
     // The shelf is not visible, and there is no nagger scheduled.
     nagger_.reset(new tray::UpdateNagger(this));
   }
 }
 
 }  // namespace ash