MacViews: Implement Full Keyboard Access.

ui/views/controls/button/checkbox.cc

Index: ui/views/controls/button/checkbox.cc
diff --git a/ui/views/controls/button/checkbox.cc b/ui/views/controls/button/checkbox.cc
index 2ab281f1943b3cf72f93768858a57efed4760c32..bf7309bb6e097f2ef47f20b1daf5ce4cf31aeae3 100644
--- a/ui/views/controls/button/checkbox.cc
+++ b/ui/views/controls/button/checkbox.cc
@@ -14,6 +14,7 @@
 #include "ui/views/controls/button/label_button_border.h"
 #include "ui/views/painter.h"
 #include "ui/views/resources/grit/views_resources.h"
+#include "ui/views/style/platform_style.h"
 
 namespace views {
 
@@ -28,7 +29,7 @@ Checkbox::Checkbox(const base::string16& label)
   // Inset the trailing side by a couple pixels for the focus border.
   button_border->set_insets(gfx::Insets(0, 0, 0, 2));
   SetBorder(std::move(button_border));
-  SetFocusable(true);
+  PlatformStyle::SetControlStyleFocus(this);
 
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();