Add a new CryptoTestUtils::LeafCertHashForTesting for generating expected leaf cert hashes.

net/quic/test_tools/crypto_test_utils.h

Index: net/quic/test_tools/crypto_test_utils.h
diff --git a/net/quic/test_tools/crypto_test_utils.h b/net/quic/test_tools/crypto_test_utils.h
index 62373abbb7d2d6c5471d96e230466f1dfa664c93..5fa199cc0b135fef95264b08514d6c4430477486 100644
--- a/net/quic/test_tools/crypto_test_utils.h
+++ b/net/quic/test_tools/crypto_test_utils.h
@@ -152,6 +152,9 @@ class CryptoTestUtils {
   // Returns a real ProofVerifier (not a fake proof verifier) for testing.
   static ProofVerifier* RealProofVerifierForTesting();
 
+  // Returns a hash of the leaf test certificate.
+  static uint64_t LeafCertHashForTesting();
+
   // Returns a |ProofVerifyContext| that must be used with the verifier
   // returned by |ProofVerifierForTesting|.
   static ProofVerifyContext* ProofVerifyContextForTesting();