MacViews: draw Mac combobox arrows

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 "build/build_config.h"
 #include "ui/base/material_design/material_design_controller.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/resources/grit/ui_resources.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/button/label_button.h"
 #include "ui/views/controls/button/label_button_border.h"
 #include "ui/views/controls/focusable_border.h"
 #include "ui/views/controls/scrollbar/native_scroll_bar.h"
 
 namespace views {
 
 #if !defined(OS_MACOSX)
 
 // static
+gfx::ImageSkia PlatformStyle::CreateComboboxArrow(bool is_enabled) {
+  gfx::ImageSkia* image =
+    ui::ResourceBundle::GetSharedInstance().GetImageSkiaNamed(

[tapted, 2016/03/29 04:16:36]

nit: The convention for this elsewhere in Chrome is typically

  ui::ResourceBundle& rb = uiResourceBundle::GetSharedInstance();
  return *rb.GetImageSkiaNamed(IDR_MENU_DROPARROW);

[Elly Fong-Jones, 2016/04/04 17:09:55]

Done.

+      IDR_MENU_DROPARROW);
+  return *image;
+}
+
+// static
 scoped_ptr<FocusableBorder> PlatformStyle::CreateComboboxBorder() {
   return make_scoped_ptr(new FocusableBorder());
 }
 
 // static
 scoped_ptr<Background> PlatformStyle::CreateComboboxBackground() {
   return nullptr;
 }
 
 // static
@@ skipping 18 matching lines @@
 
 #if !defined(OS_LINUX) || defined(OS_CHROMEOS)
 // static
 scoped_ptr<Border> PlatformStyle::CreateThemedLabelButtonBorder(
     LabelButton* button) {
   return button->CreateDefaultBorder();
 }
 #endif
 
 }  // namespace views