Pump the http version to download system.

content/browser/download/parallel_download_utils.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 "content/browser/download/parallel_download_utils.h"
 
 #include "base/metrics/field_trial_params.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "content/public/browser/download_save_info.h"
@@ skipping 25 matching lines @@
 // TODO(qinmin): replace this with a comparator operator in
 // DownloadItem::ReceivedSlice.
 bool compareReceivedSlices(const DownloadItem::ReceivedSlice& lhs,
                            const DownloadItem::ReceivedSlice& rhs) {
   return lhs.offset < rhs.offset;
 }
 
 }  // namespace
 
 bool ShouldUseParallelDownload(const DownloadCreateInfo& create_info) {
+  // To enable parallel download, following conditions need to be satisfied.
   // 1. Accept-Ranges, Content-Length and strong validators response headers.
   // 2. Feature |kParallelDownloading| enabled.
   // 3. Content-Length is no less than the minimum slice size configuration.
-  // 3. TODO(xingliu) HTTP/1.1 protocol, not QUIC or HTTP/2.
+  // 3. HTTP/1.1 protocol, not QUIC nor HTTP/1.0.
 
   // Etag and last modified are stored into DownloadCreateInfo in
   // DownloadRequestCore only if the response header complies to the strong
   // validator rule.
   bool has_strong_validator =
       !create_info.etag.empty() || !create_info.last_modified.empty();
 
   return has_strong_validator && create_info.accept_range &&
          create_info.total_bytes >= GetMinSliceSizeConfig() &&
+         create_info.connection_info ==
+             net::HttpResponseInfo::CONNECTION_INFO_HTTP1_1 &&
          base::FeatureList::IsEnabled(features::kParallelDownloading);
 }
 
 std::vector<DownloadItem::ReceivedSlice> FindSlicesForRemainingContent(
     int64_t bytes_received,
     int64_t content_length,
     int request_count) {
   std::vector<DownloadItem::ReceivedSlice> slices_to_download;
   if (request_count <= 0)
     return slices_to_download;
@@ skipping 84 matching lines @@
 base::TimeDelta GetParallelRequestDelayConfig() {
   std::string finch_value = base::GetFieldTrialParamValueByFeature(
       features::kParallelDownloading, kParallelRequestDelayFinchKey);
   int64_t time_ms = 0;
   return base::StringToInt64(finch_value, &time_ms)
              ? base::TimeDelta::FromMilliseconds(time_ms)
              : base::TimeDelta::FromMilliseconds(0);
 }
 
 }  // namespace content