Harmony - Use FocusableBorder for comboboxes on Mac

ui/views/style/mac/combobox_background_mac.h

Index: ui/views/style/mac/combobox_background_mac.h
diff --git a/ui/views/style/mac/combobox_background_mac.h b/ui/views/style/mac/combobox_background_mac.h
deleted file mode 100644
index 353deab74d7236e531990ceaaf64fa3e4ddad39b..0000000000000000000000000000000000000000
--- a/ui/views/style/mac/combobox_background_mac.h
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright 2016 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_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_
-#define UI_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_
-
-#include "base/macros.h"
-#include "ui/views/background.h"
-
-namespace gfx {
-class Canvas;
-}
-
-namespace views {
-
-// This class implements the background of comboboxes. Comboboxes look like
-// this:
-//   ---------------------------
-//   | Option Text... | Arrows |
-//   ---------------------------
-// This class colors the background of the arrows section in accordance with our
-// Mac look and feel.
-class ComboboxBackgroundMac : public Background {
- public:
-  // The |container_width| argument is the width of the "arrows" section from
-  // the diagram above, including any necessary padding around the actual arrow.
-  explicit ComboboxBackgroundMac(int container_width);
-  ~ComboboxBackgroundMac() override;
-
-  // Background:
-  void Paint(gfx::Canvas* canvas, View* view) const override;
-
- private:
-  int container_width_;
-
-  DISALLOW_COPY_AND_ASSIGN(ComboboxBackgroundMac);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_STYLE_MAC_COMBOBOX_BACKGROUND_MAC_H_