Revert of Use a single views::MenuConfig instance for each platform

ui/views/controls/menu/menu_config_aura.cc

Index: ui/views/controls/menu/menu_config_aura.cc
diff --git a/ui/views/controls/menu/menu_config_chromeos.cc b/ui/views/controls/menu/menu_config_aura.cc
similarity index 58%
rename from ui/views/controls/menu/menu_config_chromeos.cc
rename to ui/views/controls/menu/menu_config_aura.cc
index 428b1fdd8963ba8b7b68acabb41e4231ab1d8acc..a49d44744a6ce369d6ddfec4e646193a512a9713 100644
--- a/ui/views/controls/menu/menu_config_chromeos.cc
+++ b/ui/views/controls/menu/menu_config_aura.cc
@@ -4,15 +4,33 @@
 
 #include "ui/views/controls/menu/menu_config.h"
 
+#include "ui/base/layout.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_skia.h"
+#include "ui/native_theme/native_theme_aura.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/controls/menu/menu_image_util.h"
+#include "ui/views/resources/grit/views_resources.h"
 
 namespace views {
 
-void MenuConfig::Init() {
+namespace {
+#if defined(OS_CHROMEOS)
+static const int kMenuCornerRadiusForAura = 2;
+#else
+static const int kMenuCornerRadiusForAura = 0;
+#endif
+}  // namespace
+
+#if !defined(OS_WIN)
+void MenuConfig::Init(const ui::NativeTheme* theme) {
+  if (theme == ui::NativeThemeAura::instance())
+    InitAura(theme);
+}
+#endif
+
+void MenuConfig::InitAura(const ui::NativeTheme* theme) {
   submenu_horizontal_inset = 1;
   arrow_to_edge_padding = 20;
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
@@ -28,10 +46,19 @@ void MenuConfig::Init() {
   always_use_icon_to_label_padding = true;
   align_arrow_and_shortcut = true;
   offset_context_menus = true;
-  corner_radius = 2;
+  corner_radius = kMenuCornerRadiusForAura;
 
   // In Ash, the border is provided by the shadow.
   use_outer_border = false;
 }
 
+#if !defined(OS_WIN)
+// static
+const MenuConfig& MenuConfig::instance(const ui::NativeTheme* theme) {
+  CR_DEFINE_STATIC_LOCAL(MenuConfig, instance,
+                         (theme ? theme : ui::NativeThemeAura::instance()));
+  return instance;
+}
+#endif
+
 }  // namespace views