Add NativePixmapHandle type & interface for exporting them

ui/gfx/native_pixmap_handle_ozone.h

Index: ui/gfx/native_pixmap_handle_ozone.h
diff --git a/ui/gfx/native_pixmap_handle_ozone.h b/ui/gfx/native_pixmap_handle_ozone.h
new file mode 100644
index 0000000000000000000000000000000000000000..14d556080feb7cecfd1d042ddb46894e64e7fbfc
--- /dev/null
+++ b/ui/gfx/native_pixmap_handle_ozone.h
@@ -0,0 +1,22 @@
+// Copyright 2015 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_GFX_NATIVE_PIXMAP_HANDLE_OZONE_H_
+#define UI_GFX_NATIVE_PIXMAP_HANDLE_OZONE_H_
+
+#include "base/file_descriptor_posix.h"
+
+namespace gfx {
+
+struct NativePixmapHandle {
+  // A file descriptor for the underlying memory object (usually dmabuf).
+  base::FileDescriptor fd;
+
+  // The stride to used when accessing the buffer via a memory mapping.
+  int32_t stride = 0;
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_NATIVE_PIXMAP_HANDLE_OZONE_H_