[aura-mus] Add ui::CursorData, with mojo serialization.

services/ui/public/interfaces/cursor/cursor_struct_traits.h

+// Copyright 2017 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 SERVICES_UI_PUBLIC_INTERFACES_CURSOR_CURSOR_STRUCT_TRAITS_H_
+#define SERVICES_UI_PUBLIC_INTERFACES_CURSOR_CURSOR_STRUCT_TRAITS_H_
+
+#include "services/ui/public/interfaces/cursor/cursor.mojom-shared.h"
+#include "ui/base/cursor/cursor_data.h"
+
+namespace mojo {
+
+template <>
+struct StructTraits<ui::mojom::CursorDataDataView, ui::CursorData> {
+  static ui::mojom::CursorType native_type(const ui::CursorData& c) {
+    return ui::mojom::CursorType(c.native_type());
+  }
+  static uint32_t frame_delay_ms(const ui::CursorData& c) {
+    return c.frame_delay_ms();
+  }
+  static gfx::Point hotspot(const ui::CursorData& c) { return c.hotspot(); }
+  static const std::vector<SkBitmap>& cursor_frames(const ui::CursorData& c);

[Elliot Glaysher, 2017/03/30 22:53:33]

A fun learning experience: this compiles if I return cursor_frames by value
instead of const ref, but crashes at runtime.

+  static bool Read(ui::mojom::CursorDataDataView data, ui::CursorData* out);
+};
+
+}  // namespace mojo
+
+#endif  // SERVICES_UI_PUBLIC_INTERFACES_CURSOR_CURSOR_STRUCT_TRAITS_H_