MacViews: Style BUTTON_STYLE buttons using the "modern" UI

ui/views/controls/button/custom_button.cc

Index: ui/views/controls/button/custom_button.cc
diff --git a/ui/views/controls/button/custom_button.cc b/ui/views/controls/button/custom_button.cc
index fc07e0b7b0fa4bf42ef5db8e41cb481045232006..547f949b9a36cc0b2d2871e6c87802c5ae1cadfc 100644
--- a/ui/views/controls/button/custom_button.cc
+++ b/ui/views/controls/button/custom_button.cc
@@ -80,6 +80,7 @@ const CustomButton* CustomButton::AsCustomButton(const views::View* view) {
   return AsCustomButton(const_cast<views::View*>(view));
 }
 
+// static
 CustomButton* CustomButton::AsCustomButton(views::View* view) {
   if (view) {
     const char* classname = view->GetClassName();
@@ -92,7 +93,26 @@ CustomButton* CustomButton::AsCustomButton(views::View* view) {
       return static_cast<CustomButton*>(view);
     }
   }
-  return NULL;
+  return nullptr;
+}
+
+// static
+const LabelButton* CustomButton::AsLabelButton(const views::View* view) {
+  return AsLabelButton(const_cast<views::View*>(view));
+}
+
+// static
+LabelButton* CustomButton::AsLabelButton(views::View* view) {
+  if (view) {
+    const char* classname = view->GetClassName();
+    if (!strcmp(classname, Checkbox::kViewClassName) ||
+        !strcmp(classname, LabelButton::kViewClassName) ||
+        !strcmp(classname, RadioButton::kViewClassName) ||
+        !strcmp(classname, MenuButton::kViewClassName)) {
+      return static_cast<LabelButton*>(view);
+    }
+  }
+  return nullptr;
 }
 
 CustomButton::~CustomButton() {}