Add QuicStringPiece which is actually StringPiece.

net/quic/platform/impl/quic_hostname_utils_impl.h

Index: net/quic/platform/impl/quic_hostname_utils_impl.h
diff --git a/net/quic/platform/impl/quic_hostname_utils_impl.h b/net/quic/platform/impl/quic_hostname_utils_impl.h
index 7e5cd1d39c177592b329f95d4d1d21b1760a41c7..57c67473e00f651754d16755b9668f33c4443f85 100644
--- a/net/quic/platform/impl/quic_hostname_utils_impl.h
+++ b/net/quic/platform/impl/quic_hostname_utils_impl.h
@@ -6,9 +6,9 @@
 #define NET_QUIC_PLATFORM_IMPL_QUIC_HOSTNAME_UTILS_IMPL_H_
 
 #include "base/macros.h"
-#include "base/strings/string_piece.h"
 #include "net/quic/core/quic_server_id.h"
 #include "net/quic/platform/api/quic_export.h"
+#include "net/quic/platform/api/quic_string_piece.h"
 
 namespace net {
 
@@ -18,7 +18,7 @@ class QUIC_EXPORT_PRIVATE QuicHostnameUtilsImpl {
   //  (1) disallow IP addresses;
   //  (2) check that the hostname contains valid characters only; and
   //  (3) contains at least one dot.
-  static bool IsValidSNI(base::StringPiece sni);
+  static bool IsValidSNI(QuicStringPiece sni);
 
   // Convert hostname to lowercase and remove the trailing '.'.
   // WARNING: mutates |hostname| in place and returns |hostname|.