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

ui/ozone/ozone.gyp

 # Copyright 2013 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.
 
 {
   'variables': {
     'chromium_code': 1,
     # Normally, the external_ozone_platform* variables below can be
     # overridden by supplement.gypi which must exist exactly one level
     # below the top-level src directory. They can now also be set in
     # $GYP_DEFINES
     'external_ozone_platforms%': [],
     'external_ozone_platform_files%': [],
     'external_ozone_platform_deps%': [],
     'external_ozone_platform_unittest_deps%': [],
     'internal_ozone_platforms': [],
     'internal_ozone_platform_deps': [],
     'internal_ozone_platform_unittest_deps': [],
+
+    # This enables memory-mapped access to accelerated graphics buffers via
+    # the VGEM ("virtual GEM") driver. This is currently only available on
+    # Chrome OS kernels and affects code in the GBM ozone platform.
+    # TODO(dshwang): remove this flag when all gbm hardware supports vgem map.
+    # crbug.com/519587
+    'use_vgem_map%': 0,
   },
   'targets': [
     {
       # GN version: //ui/ozone:ozone_base
       'target_name': 'ozone_base',
       'type': '<(component)',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/skia/skia.gyp:skia',
         '<(DEPTH)/ui/gfx/gfx.gyp:gfx_geometry',
@@ skipping 162 matching lines @@
       'dependencies': [
         'ozone',
         '../../base/base.gyp:base',
         '../../base/base.gyp:test_support_base',
         '../../testing/gtest.gyp:gtest',
         '../gfx/gfx.gyp:gfx_geometry',
         '<@(external_ozone_platform_unittest_deps)',
         '<@(internal_ozone_platform_unittest_deps)',
       ],
     },
+    {
+      'target_name': 'vgem_map',
+      'type': 'none',
+      'conditions': [
+        ['use_vgem_map==1', {
+          'direct_dependent_settings': {
+            'defines': [
+              'USE_VGEM_MAP',
+            ],
+          },
+        }],
+      ],
+    },
   ],
   'conditions': [
     ['<(ozone_platform_caca) == 1', {
       'includes': [
         'platform/caca/caca.gypi',
       ],
     }],
     ['<(ozone_platform_cast) == 1', {
       'includes': [
         'platform/cast/cast.gypi',
       ],
     }],
     ['<(ozone_platform_egltest) == 1', {
       'includes': [
         'platform/egltest/egltest.gypi',
       ],
     }],
     ['<(ozone_platform_gbm) == 1', {
       'includes': [
         'platform/drm/gbm.gypi',
       ],
     }],
     ['<(ozone_platform_test) == 1', {
       'includes': [
         'platform/test/test.gypi',
       ],
     }],
   ],
 }