Fix compile-time error: unused variable.

components/component_updater/configurator_impl.cc

 // Copyright 2014 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/component_updater/configurator_impl.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 27 matching lines @@
 // Disables pings. Pings are the requests sent to the update server that report
 // the success or the failure of component install or update attempts.
 extern const char kSwitchDisablePings[] = "disable-pings";
 
 // Sets the URL for updates.
 const char kSwitchUrlSource[] = "url-source";
 
 // Disables differential updates.
 const char kSwitchDisableDeltaUpdates[] = "disable-delta-updates";
 
-#if defined(OS_WIN)
-// Disables background downloads.
-const char kSwitchDisableBackgroundDownloads[] = "disable-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());
 }
 
 // Returns true if falling back on an alternate, unsafe, service URL is
 // allowed. In the fallback case, the security of the component update relies
 // only on the integrity of the CRX payloads, which is self-validating.
@@ skipping 124 matching lines @@
 
 bool ConfiguratorImpl::UseBackgroundDownloader() const {
   return background_downloads_enabled_;
 }
 
 void ConfiguratorImpl::set_enable_alt_source_url(bool enable_alt_source_url) {
   fallback_to_alt_source_url_enabled_ = enable_alt_source_url;
 }
 
 }  // namespace component_updater