Remove using namespace in net/quic/quic_stream_sequencer.h

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 4f33337d6f3875c428a7d247fe33e6fb4384a9c5..a277ac01d453cc2fd572114416fe44ad499d7e43 100644
--- a/net/quic/crypto/chacha20_poly1305_encrypter_test.cc
+++ b/net/quic/crypto/chacha20_poly1305_encrypter_test.cc
@@ -4,6 +4,8 @@
 
 #include "net/quic/crypto/chacha20_poly1305_encrypter.h"
 
+#include <string>
+
 #include "net/quic/test_tools/quic_test_utils.h"
 
 using base::StringPiece;
@@ -64,11 +66,11 @@ TEST(ChaCha20Poly1305EncrypterTest, Encrypt) {
 
   for (size_t i = 0; test_vectors[i].key != nullptr; i++) {
     // Decode the test vector.
-    string key;
-    string pt;
-    string iv;
-    string aad;
-    string ct;
+    std::string key;
+    std::string pt;
+    std::string iv;
+    std::string aad;
+    std::string ct;
     ASSERT_TRUE(DecodeHexString(test_vectors[i].key, &key));
     ASSERT_TRUE(DecodeHexString(test_vectors[i].pt, &pt));
     ASSERT_TRUE(DecodeHexString(test_vectors[i].iv, &iv));