Add QuicStringPiece which is actually StringPiece.

net/quic/chromium/quic_chromium_client_stream.h

Index: net/quic/chromium/quic_chromium_client_stream.h
diff --git a/net/quic/chromium/quic_chromium_client_stream.h b/net/quic/chromium/quic_chromium_client_stream.h
index 9facd0cd0e7302431bf43921a921f794670dfa10..e2b8c1257282f0be44343ea8d5327704cec57ae5 100644
--- a/net/quic/chromium/quic_chromium_client_stream.h
+++ b/net/quic/chromium/quic_chromium_client_stream.h
@@ -22,6 +22,7 @@
 #include "net/http/http_stream.h"
 #include "net/log/net_log_with_source.h"
 #include "net/quic/core/quic_spdy_stream.h"
+#include "net/quic/platform/api/quic_string_piece.h"
 
 namespace net {
 
@@ -88,7 +89,7 @@ class NET_EXPORT_PRIVATE QuicChromiumClientStream : public QuicSpdyStream {
   // of client-side streams should be able to set the priority.
   using QuicSpdyStream::SetPriority;
 
-  int WriteStreamData(base::StringPiece data,
+  int WriteStreamData(QuicStringPiece data,
                       bool fin,
                       const CompletionCallback& callback);
   // Same as WriteStreamData except it writes data from a vector of IOBuffers,