views: refactor away PlatformStyle::BackgroundColorForMdButton

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 71 matching lines @@
   return base::MakeUnique<NativeScrollBar>(is_horizontal);
 }
 
 // static
 SkColor PlatformStyle::TextColorForButton(
     const ButtonColorByState& color_by_state,
     const LabelButton& button) {
   return color_by_state[button.state()];
 }
 
-SkColor PlatformStyle::BackgroundColorForMdButton(
-    SkColor color,
-    Button::ButtonState state) {
-  return color;
-}
-
 #endif  // OS_MACOSX
 
 #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;
@@ skipping 10 matching lines @@
 
 #if !defined(DESKTOP_LINUX)
 // static
 std::unique_ptr<Border> PlatformStyle::CreateThemedLabelButtonBorder(
     LabelButton* button) {
   return button->CreateDefaultBorder();
 }
 #endif
 
 }  // namespace views