Update from https://crrev.com/306655

net/quic/crypto/crypto_utils.cc

Index: net/quic/crypto/crypto_utils.cc
diff --git a/net/quic/crypto/crypto_utils.cc b/net/quic/crypto/crypto_utils.cc
index 67af2e9469ca622abd475b15712c82134e48dbad..c5957750654659225bc2cf0ccf796e7e476cfaaa 100644
--- a/net/quic/crypto/crypto_utils.cc
+++ b/net/quic/crypto/crypto_utils.cc
@@ -28,19 +28,21 @@ void CryptoUtils::GenerateNonce(QuicWallTime now,
   // a 4-byte timestamp + 28 random bytes.
   nonce->reserve(kNonceSize);
   nonce->resize(kNonceSize);
-  uint32 gmt_unix_time = now.ToUNIXSeconds();
+
+  uint32 gmt_unix_time = static_cast<uint32>(now.ToUNIXSeconds());
   // The time in the nonce must be encoded in big-endian because the
   // strike-register depends on the nonces being ordered by time.
   (*nonce)[0] = static_cast<char>(gmt_unix_time >> 24);
   (*nonce)[1] = static_cast<char>(gmt_unix_time >> 16);
   (*nonce)[2] = static_cast<char>(gmt_unix_time >> 8);
   (*nonce)[3] = static_cast<char>(gmt_unix_time);
+  size_t bytes_written = 4;
 
-  size_t bytes_written = sizeof(gmt_unix_time);
   if (orbit.size() == 8) {
     memcpy(&(*nonce)[bytes_written], orbit.data(), orbit.size());
     bytes_written += orbit.size();
   }
+
   random_generator->RandBytes(&(*nonce)[bytes_written],
                               kNonceSize - bytes_written);
 }