Reduce SpdyHeaderBlock copies with move semantics in shared code.

net/tools/quic/quic_spdy_client_stream.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/tools/quic/quic_spdy_client_stream.h"
 
+#include <utility>
+
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/quic_alarm.h"
 #include "net/quic/quic_client_promised_info.h"
 #include "net/quic/spdy_utils.h"
 #include "net/spdy/spdy_protocol.h"
 #include "net/tools/quic/quic_client_session.h"
 #include "net/tools/quic/spdy_balsa_utils.h"
 
@@ skipping 156 matching lines @@
     }
     MarkConsumed(iov.iov_len);
   }
   if (sequencer()->IsClosed()) {
     OnFinRead();
   } else {
     sequencer()->SetUnblocked();
   }
 }
 
-size_t QuicSpdyClientStream::SendRequest(const SpdyHeaderBlock& headers,
+size_t QuicSpdyClientStream::SendRequest(SpdyHeaderBlock headers,
                                          StringPiece body,
                                          bool fin) {
   bool send_fin_with_headers = fin && body.empty();
   size_t bytes_sent = body.size();
-  header_bytes_written_ = WriteHeaders(headers, send_fin_with_headers, nullptr);
+  header_bytes_written_ =
+      WriteHeaders(std::move(headers), send_fin_with_headers, nullptr);
   bytes_sent += header_bytes_written_;
 
   if (!body.empty()) {
     WriteOrBufferData(body, fin, nullptr);
   }
 
   return bytes_sent;
 }
 
 }  // namespace net