Downloading the json file from ChromeReader is tried several times when ERR_NETW…

components/ntp_snippets/ntp_snippets_fetcher.cc

 // Copyright 2016 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 "components/ntp_snippets/ntp_snippets_fetcher.h"
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/strings/stringprintf.h"
@@ skipping 52 matching lines @@
   url_fetcher_ = URLFetcher::Create(GURL(url), URLFetcher::POST, this);
   url_fetcher_->SetRequestContext(url_request_context_getter_.get());
   url_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                              net::LOAD_DO_NOT_SAVE_COOKIES);
   HttpRequestHeaders headers;
   headers.SetHeader("Content-Type", "application/json; charset=UTF-8");
   url_fetcher_->SetExtraRequestHeaders(headers.ToString());
   url_fetcher_->SetUploadData("application/json",
                               kUnpersonalizedRequestParameters);
   url_fetcher_->SaveResponseToTemporaryFile(file_task_runner_.get());
+
+  // Fetchers are sometimes cancelled because a network change was detected,
+  // especially at startup and after sign-in on ChromeOS. Retrying once should

[Marc Treib, 2016/03/23 11:50:08]

I would remove everything after the first line here, as it's not really
relevant/applicable in our case.

[jkrcal, 2016/03/23 21:10:28]

Done.

+  // be enough in those cases; let the fetcher retry up to 3 times just in case.
+  // http://crbug.com/163710
+  url_fetcher_->SetAutomaticallyRetryOnNetworkChanges(3);
+  // Enable fetching the files properly even with poor connection

[Marc Treib, 2016/03/23 11:50:08]

This is IMO a bit too generic - it's more "try to make a bit more robust" rather
than "enable".

[jkrcal, 2016/03/23 21:10:28]

Done.

+  url_fetcher_->SetMaxRetriesOn5xx(3);
   url_fetcher_->Start();
 }
 
 void NTPSnippetsFetcher::OnFileMoveDone(bool success) {
   if (!success) {
     DLOG(WARNING) << "Could not move file to "
                   << download_path_.LossyDisplayName();
     return;
   }
 
@@ skipping 27 matching lines @@
   source->GetResponseAsFilePath(false, &response_path);
 
   base::PostTaskAndReplyWithResult(
       file_task_runner_.get(), FROM_HERE,
       base::Bind(&base::Move, response_path, download_path_),
       base::Bind(&NTPSnippetsFetcher::OnFileMoveDone,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 }  // namespace ntp_snippets