Refactor the process of choosing validators.

src/trusted/validator_x86/ncenuminsts_x86_32.c

 /*
  * 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.
  */
 
 #ifndef NACL_TRUSTED_BUT_NOT_TCB
 #error("This file is not meant for use in the TCB")
 #endif
 
@@ skipping 82 matching lines @@
    */
   return NaClInstDecodesCorrectly(inst) &&
       (NACLi_ILLEGAL != NACL_INST(inst)->opinfo->insttype);
 }
 
 Bool NaClSegmentValidates(uint8_t* mbase,
                           size_t size,
                           NaClPcAddress vbase) {
   NaClCPUFeaturesX86 cpu_features;
   NaClValidationStatus  status;
+  /* TODO(pasko): Validator initialization can be slow, make it run only once.
+   */
+  const struct NaClValidatorInterface *validator = NaClCreateValidator();
 
   /* check if NaCl thinks the given code segment is valid. */
   NaClSetAllCPUFeatures(&cpu_features);
-  status = NaCl_ApplyValidator_x86_32(
+  status = validator->Validate(
       vbase, mbase, size,
       /* stubout_mode= */ FALSE, /* readonly_text= */ FALSE, &cpu_features,
       NULL);
   switch (status) {
     case NaClValidationSucceeded:
       return TRUE;
     default:
       return FALSE;
   }
 }