macviews: always use Aura colors when --secondary-ui-md

ui/native_theme/native_theme_mac.h

 // Copyright (c) 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.
 
 #ifndef UI_NATIVE_THEME_NATIVE_THEME_MAC_H_
 #define UI_NATIVE_THEME_NATIVE_THEME_MAC_H_
 
 #include "base/macros.h"
 #include "ui/native_theme/native_theme_base.h"
 #include "ui/native_theme/native_theme_export.h"
@@ skipping 51 matching lines @@
   // Depending on the control part being drawn, the left or the right side can
   // be given rounded corners.
   static void PaintStyledGradientButton(SkCanvas* canvas,
                                         const gfx::Rect& bounds,
                                         ButtonBackgroundType type,
                                         bool round_left,
                                         bool round_right,
                                         bool focus);
 
  private:
-  SkColor GetAuraColorWithSystemTint(NativeTheme::ColorId color_id,
-                                     const NativeTheme* base_theme) const;
-
   NativeThemeMac();
   ~NativeThemeMac() override;
 
   DISALLOW_COPY_AND_ASSIGN(NativeThemeMac);
 };
 
 }  // namespace ui
 
 #endif  // UI_NATIVE_THEME_NATIVE_THEME_MAC_H_