Remove DisplayStructTraitsTest interface.

ui/display/mojo/display_snapshot_mojo_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 UI_DISPLAY_MOJO_DISPLAY_SNAPSHOT_MOJO_STRUCT_TRAITS_H_
 #define UI_DISPLAY_MOJO_DISPLAY_SNAPSHOT_MOJO_STRUCT_TRAITS_H_
 
+#include "ipc/ipc_message_utils.h"
+#include "ui/display/mojo/display_constants_struct_traits.h"
+#include "ui/display/mojo/display_mode_struct_traits.h"
 #include "ui/display/mojo/display_snapshot_mojo.mojom.h"
 #include "ui/display/types/display_mode.h"
 #include "ui/display/types/display_snapshot_mojo.h"
+#include "ui/gfx/geometry/mojo/geometry_struct_traits.h"
 
 namespace mojo {
 
 template <>
 struct StructTraits<display::mojom::DisplaySnapshotMojoDataView,
                     std::unique_ptr<display::DisplaySnapshotMojo>> {
   static int64_t display_id(
       const std::unique_ptr<display::DisplaySnapshotMojo>& snapshot) {
     return snapshot->display_id();
   }
@@ skipping 72 matching lines @@
     return snapshot->maximum_cursor_size();
   }
 
   static bool Read(display::mojom::DisplaySnapshotMojoDataView data,
                    std::unique_ptr<display::DisplaySnapshotMojo>* out);
 };
 
 }  // namespace mojo
 
 #endif  // UI_DISPLAY_MOJO_DISPLAY_SNAPSHOT_MOJO_STRUCT_TRAITS_H_