[Mac][Material Design] Make Material Design the default.

ui/base/material_design/material_design_controller.cc

Index: ui/base/material_design/material_design_controller.cc
diff --git a/ui/base/material_design/material_design_controller.cc b/ui/base/material_design/material_design_controller.cc
index ddf60ed546e94909ac1ae96fa91d61358b2273b7..aee66b27aed524d896f61e4fec5950f9dc2ab85d 100644
--- a/ui/base/material_design/material_design_controller.cc
+++ b/ui/base/material_design/material_design_controller.cc
@@ -107,7 +107,7 @@ MaterialDesignController::Mode MaterialDesignController::DefaultMode() {
   }
 #endif  // defined(USE_OZONE)
   return MATERIAL_NORMAL;
-#elif defined(OS_LINUX)
+#elif defined(OS_LINUX) || defined(OS_MACOSX)
   return MATERIAL_NORMAL;
 #else
   return NON_MATERIAL;