Adding shutdown tracing capabilities

chrome/browser/lifetime/application_lifetime.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/lifetime/application_lifetime.h"
 
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/command_line.h"
+#include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/prefs/pref_service.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/download/download_service.h"
@@ skipping 96 matching lines @@
 
 #if defined(OS_CHROMEOS)
   chromeos::BootTimesLoader::Get()->AddLogoutTimeMarker(
       "StartedClosingWindows", false);
 #endif
   scoped_refptr<BrowserCloseManager> browser_close_manager =
       new BrowserCloseManager;
   browser_close_manager->StartClosingBrowsers();
 }
 
 void AttemptUserExit() {

[DaveMoore, 2013/09/03 17:02:48]

Why can't you always start shutdown tracing here?

[Mr4D (OOO till 08-26), 2013/09/03 17:34:34]

As you have said yourself:
On other OS'ses then ChromeOS the user / running apps can stop the logging. If
there is a user interaction stopping the shutdown it does not make much sense to
trace that.

For ChromeOS on the other hand the state->CommitPendingWrite below might be of
interest.

[DaveMoore, 2013/09/03 20:24:11]

I would want that info in the trace, and then abort the write if the user ends
up not exiting.
On 2013/09/03 17:34:34, Mr4D wrote:

 #if defined(OS_CHROMEOS)
+  StartShutdownTracing();
   chromeos::BootTimesLoader::Get()->AddLogoutTimeMarker("LogoutStarted", false);
   // Write /tmp/uptime-logout-started as well.
   const char kLogoutStarted[] = "logout-started";
   chromeos::BootTimesLoader::Get()->RecordCurrentStats(kLogoutStarted);
 
   // Login screen should show up in owner's locale.
   PrefService* state = g_browser_process->local_state();
   if (state) {
     std::string owner_locale = state->GetString(prefs::kOwnerLocale);
     if (!owner_locale.empty() &&
         state->GetString(prefs::kApplicationLocale) != owner_locale &&
         !state->IsManagedPreference(prefs::kApplicationLocale)) {
       state->SetString(prefs::kApplicationLocale, owner_locale);
+      TRACE_EVENT0("shutdown", "CommitPendingWrite");
       state->CommitPendingWrite();
     }
   }
   g_session_manager_requested_shutdown = false;
   // On ChromeOS, always terminate the browser, regardless of the result of
   // AreAllBrowsersCloseable(). See crbug.com/123107.
   chrome::NotifyAndTerminate(true);
 #else
   // Reset the restart bit that might have been set in cancelled restart
   // request.
   PrefService* pref_service = g_browser_process->local_state();
   pref_service->SetBoolean(prefs::kRestartLastSessionOnShutdown, false);
   AttemptExitInternal();
 #endif
 }
 
+void StartShutdownTracing() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  if (command_line.HasSwitch(switches::kTraceShutdown)) {
+    base::debug::CategoryFilter category_filter(
+        command_line.GetSwitchValueASCII(switches::kTraceShutdown));
+    base::debug::TraceLog::GetInstance()->SetEnabled(
+        category_filter,
+        base::debug::TraceLog::RECORD_UNTIL_FULL);
+  }
+  TRACE_EVENT0("shutdown", "AttemptUserExit");
+}
+
 // The Android implementation is in application_lifetime_android.cc
 #if !defined(OS_ANDROID)
 void AttemptRestart() {
   // TODO(beng): Can this use ProfileManager::GetLoadedProfiles instead?
   for (chrome::BrowserIterator it; !it.done(); it.Next())
     content::BrowserContext::SaveSessionState(it->profile());
 
   PrefService* pref_service = g_browser_process->local_state();
   pref_service->SetBoolean(prefs::kWasRestarted, true);
 
@@ skipping 197 matching lines @@
   //    environment is still active.
   if (browser->host_desktop_type() == chrome::HOST_DESKTOP_TYPE_NATIVE)
     return !ash::Shell::HasInstance();
   else if (browser->host_desktop_type() == chrome::HOST_DESKTOP_TYPE_ASH)
     return BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE)->empty();
 #endif
   return true;
 }
 
 }  // namespace chrome