sandbox: extract SetuidSandboxHost code from SetuidSandboxClient

sandbox/linux/sandbox_linux.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.
 
 {
   'variables': {
     'conditions': [
       ['OS=="linux"', {
         'compile_suid_client': 1,
         'compile_credentials': 1,
@@ skipping 297 matching lines @@
       ],
     },
     {
       'target_name': 'suid_sandbox_client',
       'type': '<(component)',
       'sources': [
         'suid/common/sandbox.h',
         'suid/common/suid_unsafe_environment_variables.h',
         'suid/client/setuid_sandbox_client.cc',
         'suid/client/setuid_sandbox_client.h',
+        'suid/client/setuid_sandbox_host.cc',
+        'suid/client/setuid_sandbox_host.h',
       ],
       'defines': [
         'SANDBOX_IMPLEMENTATION',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         'sandbox_services',
       ],
       'include_dirs': [
         '..',
@@ skipping 60 matching lines @@
             '../../build/isolate.gypi',
           ],
           'sources': [
             '../sandbox_linux_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }