Replace last remaining NULLs in gfe/quic with nullptr. No behavior change.

net/quic/crypto/chacha20_poly1305_encrypter_test.cc

Index: net/quic/crypto/chacha20_poly1305_encrypter_test.cc
diff --git a/net/quic/crypto/chacha20_poly1305_encrypter_test.cc b/net/quic/crypto/chacha20_poly1305_encrypter_test.cc
index 59eda378b7be8239ad1a8724d2c92a6ea6ebcd52..0c4918208e128eaad966f1e3595e47baaa8cc6de 100644
--- a/net/quic/crypto/chacha20_poly1305_encrypter_test.cc
+++ b/net/quic/crypto/chacha20_poly1305_encrypter_test.cc
@@ -14,7 +14,7 @@ namespace {
 // The test vectors come from draft-agl-tls-chacha20poly1305-04 Section 7.
 
 // Each test vector consists of five strings of lowercase hexadecimal digits.
-// The strings may be empty (zero length). A test vector with a NULL |key|
+// The strings may be empty (zero length). A test vector with a nullptr |key|
 // marks the end of an array of test vectors.
 struct TestVector {
   const char* key;
@@ -25,15 +25,13 @@ struct TestVector {
 };
 
 const TestVector test_vectors[] = {
-  { "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
+    {
+        "4290bcb154173531f314af57f3be3b5006da371ece272afa1b5dbdd110"
         "0a1007",
-    "86d09974840bded2a5ca",
-    "cd7cf67be39c794a",
-    "87e229d4500845a079c0",
-    "e3e446f7ede9a19b62a4677dabf4e3d24b876bb28475"  // "3896e1d6" truncated.
-  },
-  { NULL }
-};
+        "86d09974840bded2a5ca", "cd7cf67be39c794a", "87e229d4500845a079c0",
+        "e3e446f7ede9a19b62a4677dabf4e3d24b876bb28475"  // "3896e1d6" truncated.
+    },
+    {nullptr}};
 
 }  // namespace