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 51 matching lines @@
 using base::Time;
 using base::TimeDelta;
 using content::BrowserThread;
 
 namespace browser_shutdown {
 namespace {
 
 // Whether the browser is trying to quit (e.g., Quit chosen from menu).
 bool g_trying_to_quit = false;
 
+// If restarting and this is true then add the kNoStartupWindow switch to the
+// command line.
+bool g_should_restart_in_background = false;
+
 Time* g_shutdown_started = nullptr;
 ShutdownType g_shutdown_type = NOT_VALID;
 int g_shutdown_num_processes;
 int g_shutdown_num_processes_slow;
 
 const char kShutdownMsFile[] = "chrome_shutdown_ms.txt";
 
 const char* ToShutdownTypeString(ShutdownType type) {
   switch (type) {
     case NOT_VALID:
@@ skipping 150 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 (g_should_restart_in_background)

[sky, 2016/05/18 19:23:06]

Having a global is error prone. Can you make this a parameter to this function?

[dgn, 2016/06/20 17:45:19]

Done. It made it a static class member in BackgroundModeManager. Sadly I
couldn't make it instance member because the BMM gets cleared by the time we
want to read the value.

+      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 76 matching lines @@
 }
 
 void SetTryingToQuit(bool quitting) {
   g_trying_to_quit = quitting;
 }
 
 bool IsTryingToQuit() {
   return g_trying_to_quit;
 }
 
+void SetShouldRestartInBackground(bool should_restart_in_background) {
+  g_should_restart_in_background = should_restart_in_background;
+}
+
 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