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

ui/base/material_design/material_design_controller.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/base/material_design/material_design_controller.h"
@@ skipping 89 matching lines @@
     if (fd >= 0) {
       if (devinfo.Initialize(fd, path) && devinfo.HasTouchscreen()) {
         close(fd);
         return MATERIAL_HYBRID;
       }
       close(fd);
     }
   }
 #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;
 #endif  // defined(OS_CHROMEOS)
 }
 
 // static
 void MaterialDesignController::Uninitialize() {
   is_mode_initialized_ = false;
 }
 
 // static
 void MaterialDesignController::SetMode(MaterialDesignController::Mode mode) {
   mode_ = mode;
   is_mode_initialized_ = true;
 }
 
 }  // namespace ui