ash: Remove a few unused includes.

ash/system/chromeos/tray_tracing.cc

 // Copyright 2013 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/chromeos/tray_tracing.h"
 
 #include "ash/shell.h"
 #include "ash/system/tray/actionable_view.h"
 #include "ash/system/tray/fixed_sized_image_view.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/tray/tray_constants.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
-#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace ash {
 namespace tray {
 
 class DefaultTracingView : public ActionableView {
@@ skipping 74 matching lines @@
 }
 
 void TrayTracing::DestroyDetailedView() {
 }
 
 void TrayTracing::OnTracingModeChanged(bool value) {
   SetTrayIconVisible(value);
 }
 
 }  // namespace ash