Replace QuicString with std::string, pass 1

This replaces QuicString with std::string in all of the "QUIC proper".  I will
delete QuicString once all code using it is gone.

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 237872023
Change-Id: I82de62c9855516b15039734d05155917e68ff4ee
diff --git a/quic/core/crypto/channel_id_test.cc b/quic/core/crypto/channel_id_test.cc
index 3e03580..d904bcb 100644
--- a/quic/core/crypto/channel_id_test.cc
+++ b/quic/core/crypto/channel_id_test.cc
@@ -286,17 +286,17 @@
   std::unique_ptr<ChannelIDSource> source(
       crypto_test_utils::ChannelIDSourceForTesting());
 
-  const QuicString signed_data = "signed data";
-  const QuicString hostname = "foo.example.com";
+  const std::string signed_data = "signed data";
+  const std::string hostname = "foo.example.com";
   std::unique_ptr<ChannelIDKey> channel_id_key;
   QuicAsyncStatus status =
       source->GetChannelIDKey(hostname, &channel_id_key, nullptr);
   ASSERT_EQ(QUIC_SUCCESS, status);
 
-  QuicString signature;
+  std::string signature;
   ASSERT_TRUE(channel_id_key->Sign(signed_data, &signature));
 
-  QuicString key = channel_id_key->SerializeKey();
+  std::string key = channel_id_key->SerializeKey();
   EXPECT_TRUE(ChannelIDVerifier::Verify(key, signed_data, signature));
 
   EXPECT_FALSE(ChannelIDVerifier::Verify("a" + key, signed_data, signature));
@@ -305,14 +305,14 @@
   std::unique_ptr<char[]> bad_key(new char[key.size()]);
   memcpy(bad_key.get(), key.data(), key.size());
   bad_key[1] ^= 0x80;
-  EXPECT_FALSE(ChannelIDVerifier::Verify(QuicString(bad_key.get(), key.size()),
+  EXPECT_FALSE(ChannelIDVerifier::Verify(std::string(bad_key.get(), key.size()),
                                          signed_data, signature));
 
   std::unique_ptr<char[]> bad_signature(new char[signature.size()]);
   memcpy(bad_signature.get(), signature.data(), signature.size());
   bad_signature[1] ^= 0x80;
   EXPECT_FALSE(ChannelIDVerifier::Verify(
-      key, signed_data, QuicString(bad_signature.get(), signature.size())));
+      key, signed_data, std::string(bad_signature.get(), signature.size())));
 
   EXPECT_FALSE(ChannelIDVerifier::Verify(key, "wrong signed data", signature));
 }