Add NativePixmapHandle type & interface for exporting them

ui/gfx/native_pixmap_handle_ozone.h

+// 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 {

[dcheng, 2015/08/18 18:43:25]

Is this class copyable? It seems quite dangerous to copy a base::FileDescriptor
object with auto_close == true.

[spang, 2015/08/18 19:15:17]

Should be fine to copy with auto_close := true fine as long as you don't write
to more than one IPC::Message.

I'm not sure if we can make it not copyable. Doesn't IPC require copyable
parameters?

+  // 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_