Add ClientNativePixmap multi-planar support.

ui/gfx/mojo/buffer_types_traits.h

Index: ui/gfx/mojo/buffer_types_traits.h
diff --git a/ui/gfx/mojo/buffer_types_traits.h b/ui/gfx/mojo/buffer_types_traits.h
index 175a493be12773aecf0b6a5afb2b6dfbfe28b182..311f98e6e90c0c826d9d61c9699852a4b6d974c5 100644
--- a/ui/gfx/mojo/buffer_types_traits.h
+++ b/ui/gfx/mojo/buffer_types_traits.h
@@ -199,6 +199,9 @@ struct StructTraits<gfx::mojom::NativePixmapPlaneDataView,
   static int32_t offset(const gfx::NativePixmapPlane& plane) {
     return plane.offset;
   }
+  static uint64_t size(const gfx::NativePixmapPlane& plane) {
+    return plane.size;
+  }
   static uint64_t modifier(const gfx::NativePixmapPlane& plane) {
     return plane.modifier;
   }
@@ -206,6 +209,7 @@ struct StructTraits<gfx::mojom::NativePixmapPlaneDataView,
                    gfx::NativePixmapPlane* out) {
     out->stride = data.stride();
     out->offset = data.offset();
+    out->size = data.size();
     out->modifier = data.modifier();
     return true;
   }