Add SpdyString alias for std::string in net/spdy.

net/spdy/spdy_log_util.cc

 // Copyright 2017 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/spdy/spdy_log_util.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "net/http/http_log_util.h"
 
 namespace net {
 
-std::string ElideGoAwayDebugDataForNetLog(NetLogCaptureMode capture_mode,
-                                          base::StringPiece debug_data) {
+SpdyString ElideGoAwayDebugDataForNetLog(NetLogCaptureMode capture_mode,
+                                         base::StringPiece debug_data) {
   // Note: this logic should be kept in sync with stripGoAwayDebugData in
   // chrome/browser/resources/net_internals/log_view_painter.js.
   if (capture_mode.include_cookies_and_credentials()) {
     return debug_data.as_string();
   }
 
-  return std::string("[") + base::SizeTToString(debug_data.size()) +
-         std::string(" bytes were stripped]");
+  return SpdyString("[") + base::SizeTToString(debug_data.size()) +
+         SpdyString(" bytes were stripped]");
 }
 
 std::unique_ptr<base::ListValue> ElideSpdyHeaderBlockForNetLog(
     const SpdyHeaderBlock& headers,
     NetLogCaptureMode capture_mode) {
   auto headers_list = base::MakeUnique<base::ListValue>();
   for (SpdyHeaderBlock::const_iterator it = headers.begin();
        it != headers.end(); ++it) {
     headers_list->AppendString(
         it->first.as_string() + ": " +
         ElideHeaderValueForNetLog(capture_mode, it->first.as_string(),
                                   it->second.as_string()));
   }
   return headers_list;
 }
 
 }  // namespace net