ozone: Implement zero/one-copy texture for Ozone GBM.

ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h

Index: ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h
diff --git a/ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h b/ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h
new file mode 100644
index 0000000000000000000000000000000000000000..6d5da01a6d0359c32409ced6328cbb954d0d0886
--- /dev/null
+++ b/ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h
@@ -0,0 +1,46 @@
+// 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_OZONE_PLATFORM_DRM_GPU_CLIENT_NATIVE_PIXMAP_VGEM_H_
+#define UI_OZONE_PLATFORM_DRM_GPU_CLIENT_NATIVE_PIXMAP_VGEM_H_
+
+#include "base/file_descriptor_posix.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/native_pixmap_handle_ozone.h"
+#include "ui/ozone/public/client_native_pixmap.h"
+
+namespace ui {
+
+class ClientNativePixmapVgem : public ClientNativePixmap {
+ public:
+  static scoped_ptr<ClientNativePixmap> Create(
+      const gfx::NativePixmapHandle& handle,

[spang, 2015/08/12 21:40:03]

Could you unpack "handle" at the same place ownership of the contained fd is
taken?

scoped_ptr<ClientNativePixmap> ImportFromDmabuf(
  int dmabuf_fd, int stride, const gfx::Size& size);
  

[dshwang, 2015/08/13 11:30:56]

Done.

+      const base::FileDescriptor& vgem_handle,

[spang, 2015/08/12 21:40:03]

I'd prefer

int vgem_fd

over 

const base::FileDescriptor& vgem_handle

We should use base::ScopedFD if ownership is transferred and "int" otherwise.
base::FileDescriptor is for IPC; the "auto_close" thing is not necessary here.

[dshwang, 2015/08/13 11:30:56]

Done.

+      const gfx::Size& size);
+
+  ~ClientNativePixmapVgem() override;
+
+  // Overridden from ClientNativePixmap.
+  bool Map(void** data) override;
+  void Unmap() override;
+  void GetStride(int* stride) const override;
+
+ private:
+  ClientNativePixmapVgem(const base::FileDescriptor& vgem_handle,
+                         uint32_t vgem_bo_handle,
+                         const gfx::Size& size,
+                         int stride);
+
+  const base::FileDescriptor vgem_fd_;

[spang, 2015/08/12 21:40:03]

Same here. Wrapping the fd inside base::FileDescriptor isn't useful and we just
end up with "fd.fd" everywhere.

[dshwang, 2015/08/13 11:30:56]

Done.

+  const uint32_t vgem_bo_handle_;
+  const gfx::Size size_;
+  const int stride_;
+  void* data_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClientNativePixmapVgem);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_DRM_GPU_CLIENT_NATIVE_PIXMAP_VGEM_H_