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

ui/ozone/public/surface_factory_ozone.h

Index: ui/ozone/public/surface_factory_ozone.h
diff --git a/ui/ozone/public/surface_factory_ozone.h b/ui/ozone/public/surface_factory_ozone.h
index f7b7cbde99df2e2dbef4e443a43b66c01e187140..a9af5555ca5368333b4526888048bb98d5551560 100644
--- a/ui/ozone/public/surface_factory_ozone.h
+++ b/ui/ozone/public/surface_factory_ozone.h
@@ -6,6 +6,7 @@
 #define UI_OZONE_PUBLIC_SURFACE_FACTORY_OZONE_H_
 
 #include "base/callback.h"
+#include "base/file_descriptor_posix.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/native_library.h"
 #include "ui/gfx/geometry/rect.h"
@@ -121,6 +122,10 @@ class OZONE_BASE_EXPORT SurfaceFactoryOzone {
       BufferFormat format,
       BufferUsage usage);
 
+  // Export GpuMemoryBufferHandle from |pixmap|.
+  virtual base::FileDescriptor ExportDmaBuf(gfx::AcceleratedWidget widget,
+                                            scoped_refptr<NativePixmap> pixmap);
+
   // Returns true if overlays can be shown at z-index 0, replacing the main
   // surface. Combined with surfaceless extensions, it allows for an
   // overlay-only mode.