ozone gbm: whitelist 3 DRM ioctl code for native GpuMemoryBuffer.

ui/ozone/platform/drm/BUILD.gn

 # 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.
 
 import("//build/config/linux/pkg_config.gni")
 import("//ui/ozone/ozone.gni")
 
 declare_args() {
   use_mesa_platform_null = false
   use_drm_atomic = false
-
-  # TODO(dshwang): remove this flag when all gbm hardware supports vgem map.
-  # crbug.com/519587
-  use_vgem_map = false
 }
 
 pkg_config("libdrm") {
   packages = [ "libdrm" ]
 }
 
 source_set("drm_common") {
   sources = [
     "common/client_native_pixmap_factory_drm.cc",
     "common/client_native_pixmap_factory_drm.h",
@@ skipping 180 matching lines @@
     if (use_vgem_map) {
       defines += [ "USE_VGEM_MAP" ]
 
       sources = [
         "gpu/client_native_pixmap_vgem.cc",
         "gpu/client_native_pixmap_vgem.h",
       ]
     }
   }
 }