Update a few STYLE_BUTTON buttons in mash.

mash/example/window_type_launcher/window_type_launcher.cc

Index: mash/example/window_type_launcher/window_type_launcher.cc
diff --git a/mash/example/window_type_launcher/window_type_launcher.cc b/mash/example/window_type_launcher/window_type_launcher.cc
index 011a9b7ab4f0cf4606d53dc151f72941dd91c59e..5618c8a339472ec3eb5350243220ed9b093e6ff2 100644
--- a/mash/example/window_type_launcher/window_type_launcher.cc
+++ b/mash/example/window_type_launcher/window_type_launcher.cc
@@ -105,7 +105,6 @@ class ModalWindow : public views::WidgetDelegateView,
         color_(g_colors[g_color_index]),
         open_button_(MdTextButton::Create(this, base::ASCIIToUTF16("Moar!"))) {
     ++g_color_index %= arraysize(g_colors);
-    open_button_->SetStyle(views::Button::STYLE_BUTTON);
     AddChildView(open_button_);
   }
   ~ModalWindow() override {}