Add a mojom/StructTrait for display::Display.

ui/display/display.h

 // Copyright (c) 2012 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_DISPLAY_DISPLAY_H_
 #define UI_DISPLAY_DISPLAY_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "ui/display/display_export.h"
 #include "ui/gfx/geometry/rect.h"
 
+#if !defined(OS_IOS)
+#include "mojo/public/cpp/bindings/struct_traits.h"  // nogncheck
+#endif
+
 namespace display {
 
+#if !defined(OS_IOS)
+namespace mojom {
+class Display;
+}
+#endif
+
 // This class typically, but does not always, correspond to a physical display
 // connected to the system. A fake Display may exist on a headless system, or a
 // Display may correspond to a remote, virtual display.
 //
 // Note: The screen and display currently uses pixel coordinate
 // system. For platforms that support DIP (density independent pixel),
 // |bounds()| and |work_area| will return values in DIP coordinate
 // system, not in backing pixels.
 class DISPLAY_EXPORT Display final {
  public:
@@ skipping 129 matching lines @@
   }
 
  private:
   int64_t id_;
   gfx::Rect bounds_;
   gfx::Rect work_area_;
   float device_scale_factor_;
   Rotation rotation_;
   TouchSupport touch_support_;
   gfx::Size maximum_cursor_size_;
+
+#if !defined(OS_IOS)
+  friend struct mojo::StructTraits<display::mojom::Display, display::Display>;
+#endif
 };
 
 }  // namespace display
 
 #endif  // UI_DISPLAY_DISPLAY_H_