QUIC - (no behavior change) s/NULL/nullptr/g in .../quic/...

net/quic/crypto/proof_test.cc

Index: net/quic/crypto/proof_test.cc
diff --git a/net/quic/crypto/proof_test.cc b/net/quic/crypto/proof_test.cc
index b73471a04405989e195442687ae5df808a7b0ef7..031cba2896e3f1bb53edc13ed585351a9cfa10af 100644
--- a/net/quic/crypto/proof_test.cc
+++ b/net/quic/crypto/proof_test.cc
@@ -98,7 +98,7 @@ string LoadTestCert(const string& file_name) {
   base::FilePath certs_dir = GetTestCertsDirectory();
   scoped_refptr<X509Certificate> cert =
       ImportCertFromFile(certs_dir, "quic_" + file_name);
-  CHECK_NE(static_cast<X509Certificate*>(NULL), cert.get());
+  CHECK_NE(static_cast<X509Certificate*>(nullptr), cert.get());
 
   string der_bytes;
   CHECK(X509Certificate::GetDEREncoded(cert->os_cert_handle(), &der_bytes));