Provide metadata to validator to allow faster caching.

src/trusted/validator/validation_cache.h

Index: src/trusted/validator/validation_cache.h
diff --git a/src/trusted/validator/validation_cache.h b/src/trusted/validator/validation_cache.h
index 6cb0bb8a5546b5d99f212d6bd71e3fa696a4020b..290519e02cda1151f42c0a3551ba7bf9bb25fb4f 100644
--- a/src/trusted/validator/validation_cache.h
+++ b/src/trusted/validator/validation_cache.h
@@ -7,10 +7,15 @@
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_VALIDATION_CACHE_H_
 #define NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_VALIDATION_CACHE_H_
 
+#include <stddef.h>
+
 #include "native_client/src/include/nacl_base.h"
+#include "native_client/src/include/portability.h"
 
 EXTERN_C_BEGIN
 
+struct NaClValidationMetadata;
+
 /*
  * This interface allows the validator to query a database of validation results
  * while hiding details of how the database is implemented.
@@ -53,6 +58,13 @@ struct NaClValidationCache {
   void (*DestroyQuery)(void *query);
 };
 
+/* Helper function for identifying the code being validated. */
+extern void AddCodeIdentity(uint8_t *data,
+                            size_t size,
+                            const struct NaClValidationMetadata *metadata,
+                            struct NaClValidationCache *cache,
+                            void *query);
+
 EXTERN_C_END
 
 #endif /* NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_VALIDATION_CACHE_H_ */