Linux: make current InitializeSandbox() private.

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',
     '../build/temp_gyp/googleurl.gyp:googleurl',
     '../components/tracing.gyp:tracing',
     '../media/media.gyp:media',
@@ skipping 325 matching lines @@
     'common/quota_dispatcher.h',
     'common/request_extra_data.cc',
     'common/request_extra_data.h',
     'common/resource_dispatcher.cc',
     'common/resource_dispatcher.h',
     'common/resource_messages.cc',
     'common/resource_messages.h',
     'common/sandbox_init_mac.cc',
     'common/sandbox_init_mac.h',
     'common/sandbox_init_win.cc',
-    'common/sandbox_init_linux.cc',
     'common/sandbox_mac.h',
     'common/sandbox_mac.mm',
     'common/sandbox_linux.h',
     'common/sandbox_linux.cc',
     'common/sandbox_seccomp_bpf_linux.cc',
     'common/sandbox_seccomp_bpf_linux.h',
     'common/sandbox_util.cc',
     'common/sandbox_util.h',
     'common/sandbox_win.cc',
     'common/sandbox_win.h',
@@ skipping 227 matching lines @@
         '..\\third_party\\directxsdk\\files\\Redist\\<(input)',
         '<(output)',
         '<(PRODUCT_DIR)',
         ],
         'msvs_cygwin_shell': 1,
       },
      ]
     }],
   ],
 }