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

ui/ozone/platform/drm/gbm.gypi

Index: ui/ozone/platform/drm/gbm.gypi
diff --git a/ui/ozone/platform/drm/gbm.gypi b/ui/ozone/platform/drm/gbm.gypi
index d454717a435c07ac5fb7b5e7e7cd69eeb16f095c..3de803c5ec493979ceb10b788a33f8377a1a48ee 100644
--- a/ui/ozone/platform/drm/gbm.gypi
+++ b/ui/ozone/platform/drm/gbm.gypi
@@ -15,10 +15,6 @@
     ],
     'use_mesa_platform_null%': 0,
 
-    # TODO(dshwang): remove this flag when all gbm hardware supports vgem map.
-    # crbug.com/519587
-    'use_vgem_map%': 0,
-
     'use_drm_atomic%': 0,
   },
   'targets': [
@@ -136,7 +132,9 @@
       ],
       'conditions': [
         ['use_vgem_map==1', {
-          'defines': ['USE_VGEM_MAP'],
+          'dependencies': [
+            '../ozone/ozone.gyp:vgem_map',
+          ],
           'sources': [
             'gpu/client_native_pixmap_vgem.cc',
             'gpu/client_native_pixmap_vgem.h',