Make building seccomp-bpf a GYP condition

components/nacl.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,
   },
   'includes': [
     'nacl/nacl_defines.gypi',
@@ skipping 198 matching lines @@
                 }],
                 ['os_posix == 1 and OS != "mac"', {
                   'conditions': [
                     ['linux_use_tcmalloc==1', {
                       'dependencies': [
                         '../base/allocator/allocator.gyp:allocator',
                       ],
                     }],
                   ],
                 }],
+                ['use_seccomp_bpf == 0', {
+                  'sources!': [
+                    '../content/common/sandbox_linux/sandbox_bpf_base_policy_linux.cc',
+                    '../content/common/sandbox_linux/sandbox_init_linux.cc',
+                  ],
+                }, {
+                  'defines': ['USE_SECCOMP_BPF'],
+                }],
               ],
               'cflags': ['-fPIE'],
               'link_settings': {
                 'ldflags': ['-pie'],
               },
             },
           ],
         }],
         ['OS=="win" and target_arch=="ia32"', {
           'targets': [
@@ skipping 133 matching lines @@
         'nacl/common/nacl_types.h',
         'nacl/common/pnacl_types.cc',
         'nacl/common/pnacl_types.h',
       ],
       'include_dirs': [
         '..',
       ],
     },
   ]
 }