Implement a background downloader using BITS in Windows Chrome.

chrome/browser/component_updater/component_updater_configurator.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/component_updater/component_updater_configurator.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 35 matching lines @@
 // The default url for the v3 protocol service endpoint. Can be
 // overridden with --component-updater=url-source=someurl.
 const char kDefaultUrlSource[] = "https:" COMPONENT_UPDATER_SERVICE_ENDPOINT;
 
 // The url to send the pings to.
 const char kPingUrl[] = "http:" COMPONENT_UPDATER_SERVICE_ENDPOINT;
 
 #if defined(OS_WIN)
 // Disables differential updates.
 const char kSwitchDisableDeltaUpdates[] = "disable-delta-updates";
+// Enables background downloads.
+const char kSwitchEnableBackgroundDownloads[] = "enable-background-downloads";
 #endif  // defined(OS_WIN)
 
 // Returns true if and only if |test| is contained in |vec|.
 bool HasSwitchValue(const std::vector<std::string>& vec, const char* test) {
   if (vec.empty())
     return 0;
   return (std::find(vec.begin(), vec.end(), test) != vec.end());
 }
 
 // If there is an element of |vec| of the form |test|=.*, returns the right-
@@ skipping 33 matching lines @@
   virtual int MinimumReCheckWait() OVERRIDE;
   virtual int OnDemandDelay() OVERRIDE;
   virtual GURL UpdateUrl() OVERRIDE;
   virtual GURL PingUrl() OVERRIDE;
   virtual const char* ExtraRequestParams() OVERRIDE;
   virtual size_t UrlSizeLimit() OVERRIDE;
   virtual net::URLRequestContextGetter* RequestContext() OVERRIDE;
   virtual bool InProcess() OVERRIDE;
   virtual ComponentPatcher* CreateComponentPatcher() OVERRIDE;
   virtual bool DeltasEnabled() const OVERRIDE;
+  virtual bool UseBackgroundDownloader() const OVERRIDE;
 
  private:
   net::URLRequestContextGetter* url_request_getter_;
   std::string extra_info_;
   std::string url_source_;
   bool fast_update_;
   bool pings_enabled_;
   bool deltas_enabled_;
+  bool background_downloads_enabled_;
 };
 
 ChromeConfigurator::ChromeConfigurator(const CommandLine* cmdline,
     net::URLRequestContextGetter* url_request_getter)
       : url_request_getter_(url_request_getter),
         extra_info_(chrome::OmahaQueryParams::Get(
             chrome::OmahaQueryParams::CHROME)),
         fast_update_(false),
         pings_enabled_(false),
-        deltas_enabled_(false) {
+        deltas_enabled_(false),
+        background_downloads_enabled_(false) {
   // Parse comma-delimited debug flags.
   std::vector<std::string> switch_values;
   Tokenize(cmdline->GetSwitchValueASCII(switches::kComponentUpdater),
       ",", &switch_values);
   fast_update_ = HasSwitchValue(switch_values, kSwitchFastUpdate);
   pings_enabled_ = !HasSwitchValue(switch_values, kSwitchDisablePings);
 #if defined(OS_WIN)
   deltas_enabled_ = !HasSwitchValue(switch_values, kSwitchDisableDeltaUpdates);
+  background_downloads_enabled_ =
+      HasSwitchValue(switch_values, kSwitchEnableBackgroundDownloads);
 #else
   deltas_enabled_ = false;
 #endif
 
   url_source_ = GetSwitchArgument(switch_values, kSwitchUrlSource);
   if (url_source_.empty()) {
     url_source_ = kDefaultUrlSource;
   }
 
   // Make the extra request params, they are necessary so omaha does
@@ skipping 60 matching lines @@
   return new ComponentPatcherWin();
 #else
   return new ComponentPatcherCrossPlatform();
 #endif
 }
 
 bool ChromeConfigurator::DeltasEnabled() const {
   return deltas_enabled_;
 }
 
+bool ChromeConfigurator::UseBackgroundDownloader() const {
+  return background_downloads_enabled_;
+}
+
 ComponentUpdateService::Configurator* MakeChromeComponentUpdaterConfigurator(
     const CommandLine* cmdline, net::URLRequestContextGetter* context_getter) {
   return new ChromeConfigurator(cmdline, context_getter);
 }