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

ui/ozone/platform/drm/BUILD.gn

Index: ui/ozone/platform/drm/BUILD.gn
diff --git a/ui/ozone/platform/drm/BUILD.gn b/ui/ozone/platform/drm/BUILD.gn
index 78d332bcfb2f6acc6f7abe6a6c0204e67be6724c..9cd41a74dcb7bbc4636b5ece9b6d16adc9a43ab7 100644
--- a/ui/ozone/platform/drm/BUILD.gn
+++ b/ui/ozone/platform/drm/BUILD.gn
@@ -8,10 +8,6 @@ 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") {
@@ -205,7 +201,7 @@ if (ozone_platform_gbm) {
     }
 
     if (use_vgem_map) {
-      defines += [ "USE_VGEM_MAP" ]
+      configs += [ "//ui/ozone:vgem_map" ]
 
       sources += [
         "gpu/client_native_pixmap_vgem.cc",