Move test only MakeIOVector method to test_tools/quic_test_utils.h. No behavior change.

net/quic/core/quic_packet_creator_test.cc

Index: net/quic/core/quic_packet_creator_test.cc
diff --git a/net/quic/core/quic_packet_creator_test.cc b/net/quic/core/quic_packet_creator_test.cc
index 176a65e72d08ec2b7818150cd419229741b4992d..a8f667761743bccf3a207f4bc4dd5e2080e15f50 100644
--- a/net/quic/core/quic_packet_creator_test.cc
+++ b/net/quic/core/quic_packet_creator_test.cc
@@ -193,7 +193,7 @@ class QuicPacketCreatorTest : public ::testing::TestWithParam<TestParams> {
   }
 
   QuicIOVector MakeIOVector(StringPiece s) {
-    return ::net::MakeIOVector(s, &iov_);
+    return ::net::test::MakeIOVector(s, &iov_);
   }
 
   PendingRetransmission CreateRetransmission(
@@ -943,7 +943,7 @@ TEST_P(QuicPacketCreatorTest, ChloTooLarge) {
   message_data.reset(framer.ConstructHandshakeMessage(message));
 
   struct iovec iov;
-  QuicIOVector data_iovec(::net::MakeIOVector(
+  QuicIOVector data_iovec(::net::test::MakeIOVector(
       StringPiece(message_data->data(), message_data->length()), &iov));
   QuicFrame frame;
   EXPECT_CALL(delegate_,