Make the combobox in ContentSettingBubbleContents an actual combobox.

chrome/browser/ui/content_settings/content_setting_media_menu_model.h

Index: chrome/browser/ui/content_settings/content_setting_media_menu_model.h
diff --git a/chrome/browser/ui/content_settings/content_setting_media_menu_model.h b/chrome/browser/ui/content_settings/content_setting_media_menu_model.h
index 0c8977ec84056c454791c11e4820337d4a717c31..f2bfb30eb1c674a59dd46855b0d5a8fef980c741 100644
--- a/chrome/browser/ui/content_settings/content_setting_media_menu_model.h
+++ b/chrome/browser/ui/content_settings/content_setting_media_menu_model.h
@@ -16,6 +16,8 @@ class ContentSettingBubbleModel;
 
 // A menu model that builds the contents of the media capture devices menu in
 // the content setting bubble.
+// DEPRECATED: only used on OSX. Port OSX to
+// ContentSettingBubbleContents::MediaComboboxModel. See crbug.com/590850
 class ContentSettingMediaMenuModel : public ui::SimpleMenuModel,
                                      public ui::SimpleMenuModel::Delegate {
  public: