Remove unused references to NativeTheme in TrayPopupItemStyle.

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 "ui/views/controls/button/button.h"
 #include "ui/views/view.h"
 
 namespace base {
 class OneShotTimer;
 }  // namespace base
 
 namespace views {
 class BoxLayout;
 class CustomButton;
-class Label;
 class ProgressBar;
 }  // namespace views
 
 namespace ash {
 namespace test {
 class TrayDetailsViewTest;
 }  // namespace test
 
 class FixedSizedScrollView;
 class ScrollBorder;
@@ skipping 53 matching lines @@
   // respectively, used in the material design top-most header row. The caller
   // assumes ownership of the returned buttons.
   views::CustomButton* CreateSettingsButton(LoginStatus status);
   views::CustomButton* CreateHelpButton(LoginStatus status);
 
   TriView* tri_view() { return tri_view_; }
 
  private:
   friend class test::TrayDetailsViewTest;
 
-  // views::View:
-  void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
-
-  // Updates the style of |label_| based on the current native theme, if it
-  // exists. Only used for material design.
-  void UpdateStyle();
-
   // Overridden to handle clicks on subclass-specific views.
   virtual void HandleViewClicked(views::View* view);
 
   // Overridden to handle button presses on subclass-specific buttons.
   virtual void HandleButtonPressed(views::Button* sender,
                                    const ui::Event& event);
 
   // Creates and adds subclass-specific buttons to the title row.
   virtual void CreateExtraTitleRowButtons();
 
@@ skipping 18 matching lines @@
   SpecialPopupRow* title_row_;  // Not used in material design.
   FixedSizedScrollView* scroller_;
   views::View* scroll_content_;
   views::ProgressBar* progress_bar_;
 
   ScrollBorder* scroll_border_;  // Weak reference
 
   // The container view for the top-most title row in material design.
   TriView* tri_view_;
 
-  // The label used in the top-most title row for material design.
-  views::Label* label_;
-
   // 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_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayDetailsView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_TRAY_DETAILS_VIEW_H_