Add QuicStringPiece which is actually StringPiece.

net/quic/core/quic_spdy_session.h

Index: net/quic/core/quic_spdy_session.h
diff --git a/net/quic/core/quic_spdy_session.h b/net/quic/core/quic_spdy_session.h
index 183c5f1f97b3336a1d232aab01540c3779daec31..7ec0a01c1d2a95989b67b3edb8985310e22a070b 100644
--- a/net/quic/core/quic_spdy_session.h
+++ b/net/quic/core/quic_spdy_session.h
@@ -14,6 +14,7 @@
 #include "net/quic/core/quic_session.h"
 #include "net/quic/core/quic_spdy_stream.h"
 #include "net/quic/platform/api/quic_export.h"
+#include "net/quic/platform/api/quic_string_piece.h"
 
 namespace net {
 
@@ -235,7 +236,7 @@ class QUIC_EXPORT_PRIVATE QuicSpdySession : public QuicSession {
   // Helper for |WritevStreamData()|.
   void WriteDataFrame(
       QuicStreamId stream_id,
-      base::StringPiece data,
+      QuicStringPiece data,
       bool fin,
       QuicReferenceCountedPointer<QuicAckListenerInterface> ack_listener);