Reduce SpdyHeaderBlock copies with move semantics in shared code.

net/quic/quic_chromium_client_stream.cc

Index: net/quic/quic_chromium_client_stream.cc
diff --git a/net/quic/quic_chromium_client_stream.cc b/net/quic/quic_chromium_client_stream.cc
index 539c99094af7f41953694eed94ca95e627c1df56..a42d10d6e0cf006131f76bb606ab6ef11db27816 100644
--- a/net/quic/quic_chromium_client_stream.cc
+++ b/net/quic/quic_chromium_client_stream.cc
@@ -4,6 +4,8 @@
 
 #include "net/quic/quic_chromium_client_stream.h"
 
+#include <utility>
+
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -136,7 +138,7 @@ void QuicChromiumClientStream::OnCanWrite() {
 }
 
 size_t QuicChromiumClientStream::WriteHeaders(
-    const SpdyHeaderBlock& header_block,
+    SpdyHeaderBlock header_block,
     bool fin,
     QuicAckListenerInterface* ack_notifier_delegate) {
   if (!session()->IsCryptoHandshakeConfirmed()) {
@@ -148,7 +150,8 @@ size_t QuicChromiumClientStream::WriteHeaders(
       NetLog::TYPE_QUIC_CHROMIUM_CLIENT_STREAM_SEND_REQUEST_HEADERS,
       base::Bind(&QuicRequestNetLogCallback, id(), &header_block,
                  QuicSpdyStream::priority()));
-  return QuicSpdyStream::WriteHeaders(header_block, fin, ack_notifier_delegate);
+  return QuicSpdyStream::WriteHeaders(std::move(header_block), fin,
+                                      ack_notifier_delegate);
 }
 
 SpdyPriority QuicChromiumClientStream::priority() const {