Add QuicStringPiece which is actually StringPiece.

net/quic/core/quic_config.cc

Index: net/quic/core/quic_config.cc
diff --git a/net/quic/core/quic_config.cc b/net/quic/core/quic_config.cc
index b654a93831ae8e9507d661b04d6a82a92740c48b..3d2415a10e5870fee7712d1ff82b4f8c76769c56 100644
--- a/net/quic/core/quic_config.cc
+++ b/net/quic/core/quic_config.cc
@@ -13,6 +13,7 @@
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/platform/api/quic_bug_tracker.h"
 #include "net/quic/platform/api/quic_logging.h"
+#include "net/quic/platform/api/quic_string_piece.h"
 
 using std::string;
 
@@ -305,7 +306,7 @@ QuicErrorCode QuicFixedSocketAddress::ProcessPeerHello(
     const CryptoHandshakeMessage& peer_hello,
     HelloType hello_type,
     string* error_details) {
-  base::StringPiece address;
+  QuicStringPiece address;
   if (!peer_hello.GetStringPiece(tag_, &address)) {
     if (presence_ == PRESENCE_REQUIRED) {
       *error_details = "Missing " + QuicTagToString(tag_);