Add NativePixmapDmabufStub to finalize glCreateImageCHROMIUM on Linux.

ui/gfx/linux/native_pixmap_dmabuf.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_GFX_LINUX_NATIVE_PIXMAP_DMABUF_H_
+#define UI_GFX_LINUX_NATIVE_PIXMAP_DMABUF_H_
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "base/files/scoped_file.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "ui/gfx/client_native_pixmap.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/native_pixmap.h"
+
+namespace gfx {
+
+class GFX_EXPORT NativePixmapDmabufHelper

[reveman, 2017/06/07 21:02:37]

why a helper instead of NativePixmapDmabufBase that we derive from or just
include all functionality in NativePixmapDmabuf and have GbmBuffer just derive
from that?

[Julien Isorce, 2017/06/07 21:29:53]

I did something like that in Patch Set 13. I will come back to this solution, I
think I now see how to make it nicer. 

+    : public base::RefCountedThreadSafe<NativePixmapDmabufHelper> {

[reveman, 2017/06/07 21:02:37]

why does this need to be thread-safe refcounted?

[Julien Isorce, 2017/06/07 21:29:53]

By symmetry with scoped_refptr<GbmBuffer> in GbmPixmap. It is not present in the
other solution.

+ public:
+  explicit NativePixmapDmabufHelper(const gfx::NativePixmapHandle& handle);
+  NativePixmapDmabufHelper(std::vector<base::ScopedFD>&& fds,
+                           const std::vector<gfx::NativePixmapPlane>&& planes);
+
+  bool AreFdsValid() const;
+  size_t GetFdCount() const;
+  int GetFd(size_t plane) const;
+  int GetStride(size_t plane) const;
+  int GetOffset(size_t plane) const;
+  size_t GetSize(size_t plane) const;
+  uint64_t GetFormatModifier(size_t plane) const;
+
+ private:
+  friend class base::RefCountedThreadSafe<NativePixmapDmabufHelper>;
+
+  ~NativePixmapDmabufHelper();
+
+  std::vector<base::ScopedFD> fds_;
+  std::vector<gfx::NativePixmapPlane> planes_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativePixmapDmabufHelper);
+};
+
+class GFX_EXPORT NativePixmapDmaBuf : public gfx::NativePixmap {
+ public:
+  NativePixmapDmaBuf(const gfx::Size& size,
+                     gfx::BufferFormat format,
+                     const scoped_refptr<NativePixmapDmabufHelper>& helper);
+
+  // NativePixmap:
+  void* GetEGLClientBuffer() const override;
+  bool AreDmaBufFdsValid() const override;
+  size_t GetDmaBufFdCount() const override;
+  int GetDmaBufFd(size_t plane) const override;
+  int GetDmaBufPitch(size_t plane) const override;
+  int GetDmaBufOffset(size_t plane) const override;
+  uint64_t GetDmaBufModifier(size_t plane) const override;
+  gfx::BufferFormat GetBufferFormat() const override;
+  gfx::Size GetBufferSize() const override;
+  bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
+                            int plane_z_order,
+                            gfx::OverlayTransform plane_transform,
+                            const gfx::Rect& display_bounds,
+                            const gfx::RectF& crop_rect) override;
+  void SetProcessingCallback(
+      const ProcessingCallback& processing_callback) override;
+  gfx::NativePixmapHandle ExportHandle() override;
+
+ protected:
+  ~NativePixmapDmaBuf() override;
+
+ private:
+  gfx::Size size_;
+  gfx::BufferFormat format_;
+
+  scoped_refptr<gfx::NativePixmapDmabufHelper> helper_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativePixmapDmaBuf);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_LINUX_NATIVE_PIXMAP_DMABUF_H_