Add QuicStringPiece which is actually StringPiece.

net/quic/platform/impl/quic_url_utils_impl.cc

Index: net/quic/platform/impl/quic_url_utils_impl.cc
diff --git a/net/quic/platform/impl/quic_url_utils_impl.cc b/net/quic/platform/impl/quic_url_utils_impl.cc
index 1ef757b1fd32c93360c16cfe2850c7f1d6f928a9..092f3ad001b288e21765e5da3ec98ad9fad6abcd 100644
--- a/net/quic/platform/impl/quic_url_utils_impl.cc
+++ b/net/quic/platform/impl/quic_url_utils_impl.cc
@@ -6,18 +6,17 @@
 
 #include "url/gurl.h"
 
-using base::StringPiece;
 using std::string;
 
 namespace net {
 
 // static
-string QuicUrlUtilsImpl::HostName(StringPiece url) {
+string QuicUrlUtilsImpl::HostName(QuicStringPiece url) {
   return GURL(url).host();
 }
 
 // static
-bool QuicUrlUtilsImpl::IsValidUrl(StringPiece url) {
+bool QuicUrlUtilsImpl::IsValidUrl(QuicStringPiece url) {
   return GURL(url).is_valid();
 }