Change ui cursor identifiers to an enum class.

ui/aura/mus/window_port_mus.h

 // Copyright 2016 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.
 
 #ifndef UI_AURA_MUS_WINDOW_PORT_MUS_H_
 #define UI_AURA_MUS_WINDOW_PORT_MUS_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 268 matching lines @@
   cc::FrameSinkId frame_sink_id_;
   base::Closure pending_compositor_frame_sink_request_;
 
   cc::SurfaceInfo primary_surface_info_;
   cc::SurfaceInfo fallback_surface_info_;
 
   cc::LocalSurfaceId local_surface_id_;
   cc::LocalSurfaceIdAllocator local_surface_id_allocator_;
   gfx::Size last_surface_size_;
 
-  ui::mojom::CursorType predefined_cursor_ = ui::mojom::CursorType::CURSOR_NULL;
+  ui::mojom::CursorType predefined_cursor_ = ui::mojom::CursorType::kNull;
 
   DISALLOW_COPY_AND_ASSIGN(WindowPortMus);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_PORT_MUS_H_