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 29 matching lines @@
 
 #if defined(OS_WIN)
 #include "chrome/browser/first_run/upgrade_util_win.h"
 #include "chrome/browser/win/browser_util.h"
 #endif
 
 #if !defined(OS_ANDROID) && !defined(OS_CHROMEOS)
 #include "chrome/browser/first_run/upgrade_util.h"
 #endif
 
+#if BUILDFLAG(ENABLE_BACKGROUND)
+#include "chrome/browser/background/background_mode_manager.h"
+#endif
+
 #if defined(ENABLE_RLZ)
 #include "components/rlz/rlz_tracker.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/boot_times_recorder.h"
 #endif
 
 #if defined(ENABLE_PRINT_PREVIEW)
 #include "chrome/browser/service_process/service_process_control.h"
@@ skipping 127 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(int shutdown_flags) {
   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);
 #endif
 
 #if defined(OS_WIN)
   if (!browser_util::IsBrowserAlreadyRunning() &&
       g_shutdown_type != END_SESSION) {
     upgrade_util::SwapNewChromeExeIfPresent();
   }
 #endif
 
-  if (restart_last_session) {
+  if (shutdown_flags & RESTART_LAST_SESSION) {
 #if !defined(OS_CHROMEOS)
     // Make sure to relaunch the browser with the original command line plus
     // the Restore Last Session flag. Note that Chrome can be launched (ie.
     // through ShellExecute on Windows) with a switch argument terminator at
     // the end (double dash, as described in b/1366444) plus a URL,
     // which prevents us from appending to the command line directly (issue
     // 46182). We therefore use GetSwitches to copy the command line (it stops
     // at the switch argument terminator).
     base::CommandLine old_cl(*base::CommandLine::ForCurrentProcess());
     std::unique_ptr<base::CommandLine> new_cl(
         new base::CommandLine(old_cl.GetProgram()));
     std::map<std::string, base::CommandLine::StringType> switches =
         old_cl.GetSwitches();
     // Remove the switches that shouldn't persist across restart.
     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 (shutdown_flags & 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 70 matching lines @@
   prefs->SetInteger(prefs::kShutdownNumProcessesSlow, 0);
 
   // Read and delete the file on the file thread.
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&ReadLastShutdownFile, type, num_procs, num_procs_slow));
 }
 
 void SetTryingToQuit(bool quitting) {
   g_trying_to_quit = quitting;
+
+  if (quitting)
+    return;
+
+  // Reset the restart-related preferences.

[sky, 2016/07/22 16:57:52]

This just documents what the code is doing. Instead document why this code is
here. Why do you need to reset restart-related preferences?

[dgn, 2016/07/25 17:32:28]

Done.

+  PrefService* pref_service = g_browser_process->local_state();
+  if (pref_service) {
+#if !defined(OS_ANDROID)
+    pref_service->ClearPref(prefs::kWasRestarted);
+#endif  // !defined(OS_ANDROID)
+    pref_service->ClearPref(prefs::kRestartLastSessionOnShutdown);
+  }
+
+#if BUILDFLAG(ENABLE_BACKGROUND)
+  BackgroundModeManager::should_restart_in_background(false);
+#endif  // BUILDFLAG(ENABLE_BACKGROUND)
 }
 
 bool IsTryingToQuit() {
   return g_trying_to_quit;
 }
 
 void StartShutdownTracing() {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kTraceShutdown)) {
     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