Refactor the process of choosing validators.

src/trusted/service_runtime/service_runtime.gyp

 # -*- gyp -*-
 # Copyright (c) 2012 The Native Client 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"', {
         'syscall_handler': [
@@ skipping 187 matching lines @@
         }],
       ],
    },
   'targets': [
     {
       'target_name': 'sel',
       'type': 'static_library',
       'variables': {
         'target_base': 'sel',
       },
+      'sources': [
+          '<(DEPTH)/native_client/src/trusted/validator/validator_init.c',
+      ],
       'dependencies': [
         'env_cleanser',
         'nacl_error_code',
         '<(DEPTH)/native_client/src/shared/gio/gio.gyp:gio',
         '<(DEPTH)/native_client/src/shared/platform/platform.gyp:platform',
         '<(DEPTH)/native_client/src/shared/srpc/srpc.gyp:nonnacl_srpc',
         '<(DEPTH)/native_client/src/trusted/debug_stub/debug_stub.gyp:debug_stub',
         '<(DEPTH)/native_client/src/trusted/desc/desc.gyp:nrd_xfer',
         '<(DEPTH)/native_client/src/trusted/fault_injection/fault_injection.gyp:nacl_fault_inject',
         '<(DEPTH)/native_client/src/trusted/gdb_rsp/gdb_rsp.gyp:gdb_rsp',
@@ skipping 189 matching lines @@
             '<(DEPTH)/native_client/src/trusted/platform_qualify/platform_qualify.gyp:platform_qual_lib64',
           ],
           'sources': [
             'sel_main_chrome_test.c',
           ],
         },
       ],
     }],
   ]
 }