Moves QuicTag typedefs, and QuicTag utility methods to quic_tag.{h,cc}. No behavior change.

net/quic/core/crypto/crypto_server_test.cc

Index: net/quic/core/crypto/crypto_server_test.cc
diff --git a/net/quic/core/crypto/crypto_server_test.cc b/net/quic/core/crypto/crypto_server_test.cc
index 2ec666f0b932b21f612bff441f3a4122ea7d1d18..282e08bd872813a9d0bec79e4218f87bb7e730b2 100644
--- a/net/quic/core/crypto/crypto_server_test.cc
+++ b/net/quic/core/crypto/crypto_server_test.cc
@@ -119,7 +119,7 @@ class CryptoServerTest : public ::testing::TestWithParam<TestParams> {
 
     client_version_ = supported_versions_.front();
     client_version_string_ =
-        QuicUtils::TagToString(QuicVersionToQuicTag(client_version_));
+        QuicTagToString(QuicVersionToQuicTag(client_version_));
 
     FLAGS_quic_require_handshake_confirmation_pre33 = false;
     FLAGS_enable_quic_stateless_reject_support =
@@ -381,9 +381,9 @@ class CryptoServerTest : public ::testing::TestWithParam<TestParams> {
 
   void CheckRejectTag() {
     if (RejectsAreStateless()) {
-      ASSERT_EQ(kSREJ, out_.tag()) << QuicUtils::TagToString(out_.tag());
+      ASSERT_EQ(kSREJ, out_.tag()) << QuicTagToString(out_.tag());
     } else {
-      ASSERT_EQ(kREJ, out_.tag()) << QuicUtils::TagToString(out_.tag());
+      ASSERT_EQ(kREJ, out_.tag()) << QuicTagToString(out_.tag());
     }
   }
 
@@ -718,7 +718,7 @@ TEST_P(CryptoServerTest, DowngradeAttack) {
   // Set the client's preferred version to a supported version that
   // is not the "current" version (supported_versions_.front()).
   string bad_version =
-      QuicUtils::TagToString(QuicVersionToQuicTag(supported_versions_.back()));
+      QuicTagToString(QuicVersionToQuicTag(supported_versions_.back()));
 
   // clang-format off
   CryptoHandshakeMessage msg = CryptoTestUtils::Message(
@@ -1107,7 +1107,7 @@ class CryptoServerTestOldVersion : public CryptoServerTest {
   void SetUp() override {
     client_version_ = supported_versions_.back();
     client_version_string_ =
-        QuicUtils::TagToString(QuicVersionToQuicTag(client_version_));
+        QuicTagToString(QuicVersionToQuicTag(client_version_));
     CryptoServerTest::SetUp();
   }
 };