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/crypto_secret_boxer_test.cc b/quic/core/crypto/crypto_secret_boxer_test.cc
index d060051..8739977 100644
--- a/quic/core/crypto/crypto_secret_boxer_test.cc
+++ b/quic/core/crypto/crypto_secret_boxer_test.cc
@@ -17,29 +17,30 @@
   QuicStringPiece message("hello world");
 
   CryptoSecretBoxer boxer;
-  boxer.SetKeys({QuicString(CryptoSecretBoxer::GetKeySize(), 0x11)});
+  boxer.SetKeys({std::string(CryptoSecretBoxer::GetKeySize(), 0x11)});
 
-  const QuicString box = boxer.Box(QuicRandom::GetInstance(), message);
+  const std::string box = boxer.Box(QuicRandom::GetInstance(), message);
 
-  QuicString storage;
+  std::string storage;
   QuicStringPiece result;
   EXPECT_TRUE(boxer.Unbox(box, &storage, &result));
   EXPECT_EQ(result, message);
 
-  EXPECT_FALSE(boxer.Unbox(QuicString(1, 'X') + box, &storage, &result));
-  EXPECT_FALSE(boxer.Unbox(box.substr(1, QuicString::npos), &storage, &result));
-  EXPECT_FALSE(boxer.Unbox(QuicString(), &storage, &result));
+  EXPECT_FALSE(boxer.Unbox(std::string(1, 'X') + box, &storage, &result));
+  EXPECT_FALSE(
+      boxer.Unbox(box.substr(1, std::string::npos), &storage, &result));
+  EXPECT_FALSE(boxer.Unbox(std::string(), &storage, &result));
   EXPECT_FALSE(boxer.Unbox(
-      QuicString(1, box[0] ^ 0x80) + box.substr(1, QuicString::npos), &storage,
-      &result));
+      std::string(1, box[0] ^ 0x80) + box.substr(1, std::string::npos),
+      &storage, &result));
 }
 
 // Helper function to test whether one boxer can decode the output of another.
 static bool CanDecode(const CryptoSecretBoxer& decoder,
                       const CryptoSecretBoxer& encoder) {
   QuicStringPiece message("hello world");
-  const QuicString boxed = encoder.Box(QuicRandom::GetInstance(), message);
-  QuicString storage;
+  const std::string boxed = encoder.Box(QuicRandom::GetInstance(), message);
+  std::string storage;
   QuicStringPiece result;
   bool ok = decoder.Unbox(boxed, &storage, &result);
   if (ok) {
@@ -49,8 +50,8 @@
 }
 
 TEST_F(CryptoSecretBoxerTest, MultipleKeys) {
-  QuicString key_11(CryptoSecretBoxer::GetKeySize(), 0x11);
-  QuicString key_12(CryptoSecretBoxer::GetKeySize(), 0x12);
+  std::string key_11(CryptoSecretBoxer::GetKeySize(), 0x11);
+  std::string key_12(CryptoSecretBoxer::GetKeySize(), 0x12);
 
   CryptoSecretBoxer boxer_11, boxer_12, boxer;
   boxer_11.SetKeys({key_11});