Make building seccomp-bpf a GYP condition

content/content_common.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../components/tracing.gyp:tracing',
     '../net/net.gyp:net',
     '../skia/skia.gyp:skia',
@@ skipping 617 matching lines @@
           'python',
         '../build/extract_from_cab.py',
         '..\\third_party\\directxsdk\\files\\Redist\\<(input)',
         '<(output)',
         '<(PRODUCT_DIR)',
         ],
         'msvs_cygwin_shell': 1,
       },
      ]
     }],
+    ['use_seccomp_bpf==0', {
+      'sources!': [
+        'common/sandbox_linux/bpf_cros_arm_gpu_policy_linux.cc',
+        'common/sandbox_linux/bpf_cros_arm_gpu_policy_linux.h',
+        'common/sandbox_linux/bpf_gpu_policy_linux.cc',
+        'common/sandbox_linux/bpf_gpu_policy_linux.h',
+        'common/sandbox_linux/bpf_ppapi_policy_linux.cc',
+        'common/sandbox_linux/bpf_ppapi_policy_linux.h',
+        'common/sandbox_linux/bpf_renderer_policy_linux.cc',
+        'common/sandbox_linux/bpf_renderer_policy_linux.h',
+        'common/sandbox_linux/sandbox_bpf_base_policy_linux.cc',
+        'common/sandbox_linux/sandbox_bpf_base_policy_linux.h',
+      ],
+    }, {
+      'defines': ['USE_SECCOMP_BPF'],
+    }],
   ],
 }