Introduce ERR_NETWORK_CHANGED and allow URLFetcher to automatically retry on that error.

chrome/browser/history/web_history_service.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 "chrome/browser/history/web_history_service.h"
 
 #include "base/json/json_reader.h"
 #include "base/values.h"
 #include "chrome/browser/signin/oauth2_token_service.h"
 #include "chrome/browser/signin/oauth2_token_service_factory.h"
@@ skipping 82 matching lines @@
     token_request_.reset();
     LOG(WARNING) << "Failed to get OAuth token: " << error.ToString();
     query_history_callback_.Run(this, NULL);
   }
 
   // Helper for creating a new URLFetcher for the API request.
   net::URLFetcher* CreateUrlFetcher(const std::string& access_token) {
     net::URLFetcher* fetcher = net::URLFetcher::Create(
         url_, net::URLFetcher::GET, this);
     fetcher->SetRequestContext(profile_->GetRequestContext());
-    fetcher->SetMaxRetries(kMaxRetries);
+    fetcher->SetMaxRetriesOn5xx(kMaxRetries);
     fetcher->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                           net::LOAD_DO_NOT_SAVE_COOKIES);
     fetcher->AddExtraRequestHeader("Authorization: Bearer " + access_token);
     return fetcher;
   }
 
   Profile* profile_;
 
   // The URL of the API endpoint.
   GURL url_;
@@ skipping 28 matching lines @@
     const string16& text_query,
     const QueryOptions& options,
     const WebHistoryService::QueryWebHistoryCallback& callback) {
   scoped_ptr<RequestImpl> request(
       new RequestImpl(profile_, kHistoryGetHistoryUrl, callback));
   request->Start();
   return request.PassAs<Request>();
 }
 
 }  // namespace history