Clean up NativeTheme (particularly CommonTheme).

ui/views/style/platform_style.cc

 // Copyright 2015 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 "ui/views/style/platform_style.h"
 
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 72 matching lines @@
 #if !defined(DESKTOP_LINUX) && !defined(OS_MACOSX)
 // static
 void PlatformStyle::ApplyLabelButtonTextStyle(
     Label* label,
     ButtonColorByState* color_by_state) {
   ButtonColorByState& colors = *color_by_state;
   colors[Button::STATE_NORMAL] = kStyleButtonTextColor;
   colors[Button::STATE_HOVERED] = kStyleButtonTextColor;
   colors[Button::STATE_PRESSED] = kStyleButtonTextColor;
 
-  const ui::NativeTheme* theme = label->GetNativeTheme();
-  label->SetBackgroundColor(
-      theme->GetSystemColor(ui::NativeTheme::kColorId_ButtonBackgroundColor));
-  label->SetAutoColorReadabilityEnabled(false);
   label->SetShadows(gfx::ShadowValues(
       1, gfx::ShadowValue(gfx::Vector2d(0, 1), 0, kStyleButtonShadowColor)));
 }
 #endif
 
 #if !defined(DESKTOP_LINUX)
 // static
 std::unique_ptr<Border> PlatformStyle::CreateThemedLabelButtonBorder(
     LabelButton* button) {
   return button->CreateDefaultBorder();
 }
 #endif
 
 }  // namespace views