Implement DRM Native Pixmap using prime buffer

ui/ozone/platform/drm/gpu/gbm_surface_factory.cc

 // Copyright 2014 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.
 
 #include "ui/ozone/platform/drm/gpu/gbm_surface_factory.h"
 
 #include <gbm.h>
 
 #include "base/files/file_path.h"
 #include "build/build_config.h"
@@ skipping 78 matching lines @@
   return scanout_formats;
 }
 
 scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmap(
     gfx::AcceleratedWidget widget,
     gfx::Size size,
     gfx::BufferFormat format,
     gfx::BufferUsage usage) {
 #if !defined(OS_CHROMEOS)
   // Support for memory mapping accelerated buffers requires some
-  // CrOS-specific patches (using vgem).
+  // CrOS-specific patches (using dma-buf mmap API).
   DCHECK(gfx::BufferUsage::SCANOUT == usage);
 #endif
 
   scoped_refptr<GbmBuffer> buffer =
       drm_thread_->CreateBuffer(widget, size, format, usage);
   if (!buffer.get())
     return nullptr;
 
   return make_scoped_refptr(new GbmPixmap(this, buffer));
 }
 
 scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmapFromHandle(
     gfx::Size size,
     gfx::BufferFormat format,
     const gfx::NativePixmapHandle& handle) {
   scoped_refptr<GbmBuffer> buffer = drm_thread_->CreateBufferFromFD(
       size, format, base::ScopedFD(handle.fd.fd), handle.stride);
   if (!buffer)
     return nullptr;
 
   return make_scoped_refptr(new GbmPixmap(this, buffer));
 }
 
 }  // namespace ui