Add BackgroundModeOptimizer that can restart the browser

chrome/browser/browser_shutdown.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/browser_shutdown.h"
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
@@ skipping 176 matching lines @@
 
 #if defined(ENABLE_RLZ)
   // Cleanup any statics created by RLZ. Must be done before NotificationService
   // is destroyed.
   rlz::RLZTracker::CleanupRlz();
 #endif
 
   return restart_last_session;
 }
 
-void ShutdownPostThreadsStop(bool restart_last_session) {
+void ShutdownPostThreadsStop(bool restart_last_session,
+                             bool restart_in_background) {
   delete g_browser_process;
   g_browser_process = NULL;
 
   // crbug.com/95079 - This needs to happen after the browser process object
   // goes away.
   ProfileManager::NukeDeletedProfilesFromDisk();
 
 #if defined(OS_CHROMEOS)
   chromeos::BootTimesRecorder::Get()->AddLogoutTimeMarker("BrowserDeleted",
                                                           true);
@@ skipping 24 matching lines @@
     about_flags::RemoveFlagsSwitches(&switches);
     switches::RemoveSwitchesForAutostart(&switches);
     // Append the old switches to the new command line.
     for (const auto& it : switches) {
       const base::CommandLine::StringType& switch_value = it.second;
       if (!switch_value.empty())
         new_cl->AppendSwitchNative(it.first, it.second);
       else
         new_cl->AppendSwitch(it.first);
     }
+    if (restart_in_background)
+      new_cl->AppendSwitch(switches::kNoStartupWindow);
 
 #if defined(OS_POSIX) || defined(OS_WIN)
     upgrade_util::RelaunchChromeBrowser(*new_cl.get());
 #endif  // defined(OS_WIN)
 
 #else
     NOTIMPLEMENTED();
 #endif  // !defined(OS_CHROMEOS)
   }
 
@@ skipping 90 matching lines @@
     base::trace_event::TraceConfig trace_config(
         command_line.GetSwitchValueASCII(switches::kTraceShutdown), "");
     content::TracingController::GetInstance()->StartTracing(
         trace_config,
         content::TracingController::StartTracingDoneCallback());
   }
   TRACE_EVENT0("shutdown", "StartShutdownTracing");
 }
 
 }  // namespace browser_shutdown