Add a new QUIC platform API for text utilities.

net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc

Index: net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc
diff --git a/net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc b/net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc
index 453902439fb909919716c9d42c4c50e45576b55c..4a04d21af3d9659e2f0cabf5493de1b7ab244f32 100644
--- a/net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc
+++ b/net/quic/core/crypto/aes_128_gcm_12_decrypter_test.cc
@@ -7,6 +7,7 @@
 #include <memory>
 
 #include "net/quic/core/quic_utils.h"
+#include "net/quic/platform/api/quic_text_utils.h"
 #include "net/quic/test_tools/quic_test_utils.h"
 
 using base::StringPiece;
@@ -232,14 +233,14 @@ TEST(Aes128Gcm12DecrypterTest, Decrypt) {
       bool has_pt = test_vectors[j].pt;
 
       // Decode the test vector.
-      string key = QuicUtils::HexDecode(test_vectors[j].key);
-      string iv = QuicUtils::HexDecode(test_vectors[j].iv);
-      string ct = QuicUtils::HexDecode(test_vectors[j].ct);
-      string aad = QuicUtils::HexDecode(test_vectors[j].aad);
-      string tag = QuicUtils::HexDecode(test_vectors[j].tag);
+      string key = QuicTextUtils::HexDecode(test_vectors[j].key);
+      string iv = QuicTextUtils::HexDecode(test_vectors[j].iv);
+      string ct = QuicTextUtils::HexDecode(test_vectors[j].ct);
+      string aad = QuicTextUtils::HexDecode(test_vectors[j].aad);
+      string tag = QuicTextUtils::HexDecode(test_vectors[j].tag);
       string pt;
       if (has_pt) {
-        pt = QuicUtils::HexDecode(test_vectors[j].pt);
+        pt = QuicTextUtils::HexDecode(test_vectors[j].pt);
       }
 
       // The test vector's lengths should look sane. Note that the lengths