Reduce SpdyHeaderBlock copies with move semantics in shared code.

net/quic/quic_chromium_client_stream.h

 // 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.
 //
 // NOTE: This code is not shared between Google and Chrome.
 
 #ifndef NET_QUIC_QUIC_CHROMIUM_CLIENT_STREAM_H_
 #define NET_QUIC_QUIC_CHROMIUM_CLIENT_STREAM_H_
 
 #include <stddef.h>
@@ skipping 58 matching lines @@
                                 size_t frame_len,
                                 const QuicHeaderList& header_list) override;
   void OnTrailingHeadersComplete(bool fin,
                                  size_t frame_len,
                                  const QuicHeaderList& header_list) override;
   void OnPromiseHeadersComplete(QuicStreamId promised_stream_id,
                                 size_t frame_len) override;
   void OnDataAvailable() override;
   void OnClose() override;
   void OnCanWrite() override;
-  size_t WriteHeaders(const SpdyHeaderBlock& header_block,
+  size_t WriteHeaders(SpdyHeaderBlock header_block,
                       bool fin,
                       QuicAckListenerInterface* ack_notifier_delegate) override;
   SpdyPriority priority() const override;
 
   // While the server's set_priority shouldn't be called externally, the creator
   // of client-side streams should be able to set the priority.
   using QuicSpdyStream::SetPriority;
 
   int WriteStreamData(base::StringPiece data,
                       bool fin,
@@ skipping 55 matching lines @@
   std::deque<base::Closure> delegate_tasks_;
 
   base::WeakPtrFactory<QuicChromiumClientStream> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicChromiumClientStream);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CHROMIUM_CLIENT_STREAM_H_