add a download slices table into history download db

chrome/common/chrome_features.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 "chrome/common/chrome_features.h"
 
 #include "extensions/features/features.h"
 #include "ppapi/features/features.h"
 
 namespace features {
@@ skipping 155 matching lines @@
 
 // If enabled, the list of content suggestions on the New Tab page will contain
 // pages that the user downloaded for later use.
 const base::Feature kOfflinePageDownloadSuggestionsFeature{
     "NTPOfflinePageDownloadSuggestions", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables YouTube Flash videos to be overridden.
 const base::Feature kOverrideYouTubeFlashEmbed{
     "OverrideYouTubeFlashEmbed", base::FEATURE_ENABLED_BY_DEFAULT};
 
-const base::Feature kParallelDownloading{
-    "ParallelDownloading", base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Enables Permissions Blacklisting via Safe Browsing.
 const base::Feature kPermissionsBlacklist{
     "PermissionsBlacklist", base::FEATURE_DISABLED_BY_DEFAULT};
 
 #if BUILDFLAG(ENABLE_PLUGINS)
 // Prefer HTML content by hiding Flash from the list of plugins.
 // https://crbug.com/626728
 const base::Feature kPreferHtmlOverPlugins{"PreferHtmlOverPlugins",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
@@ skipping 65 matching lines @@
 // Enables or disables emoji, handwriting and voice input on opt-in IME menu.
 const base::Feature kEHVInputOnImeMenu{"EmojiHandwritingVoiceInput",
                                        base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enables or disables flash component updates on Chrome OS.
 const base::Feature kCrosCompUpdates{"CrosCompUpdates",
                                      base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace features