Write a NativeThemeGtk2 class for linux_aura.

ui/views/controls/menu/menu_item_view.cc

 // Copyright (c) 2012 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/controls/menu/menu_item_view.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/stl_util.h"
 #include "base/utf_string_conversions.h"
 #include "grit/ui_resources.h"
@@ skipping 774 matching lines @@
   // only need the background when we want it to look different, as when we're
   // selected.
   ui::NativeTheme* native_theme = GetNativeTheme();
   SkColor override_color;
   if (GetDelegate() &&
       GetDelegate()->GetBackgroundColor(GetCommand(),
                                         render_selection,
                                         &override_color)) {
     canvas->DrawColor(override_color);
   } else if (render_selection) {
+    // TODO(erg): The following doesn't actually get the focused menu item
+    // background for times when we want to match the native OS.
     if (ui::NativeTheme::IsNewMenuStyleEnabled()) {
       gfx::Rect item_bounds(0, 0, width(), height());
       AdjustBoundsForRTLUI(&item_bounds);
       CommonThemePaintMenuItemBackground(canvas->sk_canvas(),
           ui::NativeTheme::kHovered, item_bounds);
     } else {
       SkColor bg_color = native_theme->GetSystemColor(
           ui::NativeTheme::kColorId_FocusedMenuItemBackgroundColor);
       canvas->DrawColor(bg_color, SkXfermode::kSrc_Mode);
     }
@@ skipping 246 matching lines @@
     } else {
       const Type& type = menu_item->GetType();
       if (type == CHECKBOX || type == RADIO)
         return true;
     }
   }
   return false;
 }
 
 }  // namespace views