Allow auto-retries on network changed errors in the component updater.

The retries are set to 3, as most of the Chromium code using the
url fetcher does.

Bug: 842364
Change-Id: I0f6e295231c36301c6ca44806233f841d316b58e
Reviewed-on: https://chromium-review.googlesource.com/1056222Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Sorin Jianu <sorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558374}

components/update_client/url_fetcher_downloader.cc

@@ -142,6 +142,7 @@ void UrlFetcherDownloader::StartURLFetch(const GURL& url) {
                              net::LOAD_DO_NOT_SAVE_COOKIES |
                              net::LOAD_DISABLE_CACHE);
   url_fetcher_->SetAutomaticallyRetryOn5xx(false);
+  url_fetcher_->SetAutomaticallyRetryOnNetworkChanges(3);
   url_fetcher_->SaveResponseToFileAtPath(
       response, base::CreateSequencedTaskRunnerWithTraits(kTaskTraits));
   data_use_measurement::DataUseUserData::AttachToFetcher(

components/update_client/utils.cc

@@ -86,6 +86,7 @@ std::unique_ptr<net::URLFetcher> SendProtocolRequest(
                             net::LOAD_DO_NOT_SAVE_COOKIES |
                             net::LOAD_DISABLE_CACHE);
   url_fetcher->SetAutomaticallyRetryOn5xx(false);
+  url_fetcher->SetAutomaticallyRetryOnNetworkChanges(3);
   for (const auto& header : protocol_request_extra_headers)
     url_fetcher->AddExtraRequestHeader(base::StringPrintf(
         "%s: %s", header.first.c_str(), header.second.c_str()));