[Ozone-DRI] Use dma_buf rather than EGLClientBuffer

ui/ozone/platform/dri/gbm_buffer.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/dri/gbm_buffer.h"
 
 #include <drm.h>
 #include <fcntl.h>
 #include <gbm.h>
 #include <xf86drm.h>
@@ skipping 68 matching lines @@
   }
   return true;
 }
 
 GbmPixmap::~GbmPixmap() {
   if (dma_buf_ > 0)
     close(dma_buf_);
 }
 
 void* GbmPixmap::GetEGLClientBuffer() {
-  // TODO(achaulk): change back to null when dma_buf bug is fixed.
-  return buffer_->bo();
+  return nullptr;
 }
 
 int GbmPixmap::GetDmaBufFd() {
   return dma_buf_;
 }
 
 int GbmPixmap::GetDmaBufPitch() {
   return gbm_bo_get_stride(buffer_->bo());
 }
 
 }  // namespace ui