Add validation caching interface.

src/trusted/validator/ncvalidate.h

Index: src/trusted/validator/ncvalidate.h
diff --git a/src/trusted/validator/ncvalidate.h b/src/trusted/validator/ncvalidate.h
index b62d6a2ff56dac5cd9f951cd72c74e5c1a580fe9..498ccca07691cbb941cd0fb0b26031c048d2289a 100644
--- a/src/trusted/validator/ncvalidate.h
+++ b/src/trusted/validator/ncvalidate.h
@@ -30,6 +30,8 @@
 
 EXTERN_C_BEGIN
 
+struct NaClValidationCache;
+
 /* Defines the API to select the validator kind.
  * So far only the ARM architecture has a non-default validator kind
  *
@@ -110,7 +112,8 @@ extern NaClValidationStatus NACL_SUBARCH_NAME(ApplyValidator,
     uint8_t                 *data,
     size_t                  size,
     int                     bundle_size,
-    NaClCPUFeatures         *cpu_features);
+    NaClCPUFeatures         *cpu_features,
+    struct NaClValidationCache *cache);
 
 /* Applies the validator, as used in a command-line tool to report issues.
  * Note: This is intentionally separated from ApplyValidator, since it need