Replace the existing SpdyHeaderBlock typedef with a class.

net/quic/spdy_utils.cc

 // Copyright (c) 2013 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/quic/spdy_utils.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "net/spdy/spdy_frame_builder.h"
 #include "net/spdy/spdy_framer.h"
 #include "net/spdy/spdy_protocol.h"
 
 using std::string;
 
 namespace net {
 
 // static
 SpdyMajorVersion SpdyUtils::GetSpdyVersionForQuicVersion(
     QuicVersion quic_version) {
   if (quic_version > QUIC_VERSION_24) {
     return HTTP2;
   }
   return SPDY3;
 }
 
 // static
 SpdyHeaderBlock SpdyUtils::ConvertSpdy3ResponseHeadersToSpdy4(
     SpdyHeaderBlock response_headers) {
   // SPDY/4 headers include neither the version field nor the response details.
   response_headers.erase(":version");
-  size_t end_of_code = response_headers[":status"].find(' ');
+  StringPiece status_value = response_headers[":status"];
+  size_t end_of_code = status_value.find(' ');
   if (end_of_code != string::npos) {
-    response_headers[":status"].erase(end_of_code);
+    response_headers[":status"] = status_value.substr(0, end_of_code);
   }
   return response_headers;
 }
 
 // static
 string SpdyUtils::SerializeUncompressedHeaders(const SpdyHeaderBlock& headers,
                                                QuicVersion quic_version) {
   SpdyMajorVersion spdy_version = GetSpdyVersionForQuicVersion(quic_version);
 
   size_t length = SpdyFramer::GetSerializedLength(spdy_version, &headers);
   SpdyFrameBuilder builder(length, spdy_version);
   SpdyFramer::WriteHeaderBlock(&builder, spdy_version, &headers);
   scoped_ptr<SpdyFrame> block(builder.take());
   return string(block->data(), length);
 }
 
 }  // namespace net