Do not CreateSentinel until after the process singleton has been grabbed by the current process.

chrome/browser/first_run/first_run.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/first_run/first_run.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 424 matching lines @@
       ShellIntegration::SetAsDefaultBrowser();
     }
   } else {
     if (g_browser_process->local_state()->GetBoolean(
             prefs::kDefaultBrowserSettingEnabled)) {
       ShellIntegration::SetAsDefaultBrowser();
     }
   }
 }
 
+bool CreateSentinel() {
+  base::FilePath first_run_sentinel;
+  if (!internal::GetFirstRunSentinelFilePath(&first_run_sentinel))
+    return false;
+  return file_util::WriteFile(first_run_sentinel, "", 0) != -1;
+}
+
 // -- Platform-specific functions --
 
 #if !defined(OS_LINUX) && !defined(OS_BSD)
 bool IsOrganicFirstRun() {
   std::string brand;
   google_util::GetBrand(&brand);
   return google_util::IsOrganicFirstRun(brand);
 }
 #endif
 
 }  // namespace internal
 
 MasterPrefs::MasterPrefs()
     : ping_delay(0),
       homepage_defined(false),
       do_import_items(0),
       dont_import_items(0),
       make_chrome_default(false),
       suppress_first_run_default_browser_prompt(false) {
 }
 
 MasterPrefs::~MasterPrefs() {}
 
 bool IsChromeFirstRun() {
   if (internal::first_run_ != internal::FIRST_RUN_UNKNOWN)
     return internal::first_run_ == internal::FIRST_RUN_TRUE;
 
-  enum FirstRunState {
-    CANCEL_FIRST_RUN,
-    NOT_FIRST_RUN,
-    IS_FIRST_RUN,
-  };
-
-  FirstRunState first_run_state = NOT_FIRST_RUN;
+  internal::first_run_ = internal::FIRST_RUN_FALSE;
 
   base::FilePath first_run_sentinel;
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kForceFirstRun)) {
-    first_run_state = IS_FIRST_RUN;
+    internal::first_run_ = internal::FIRST_RUN_TRUE;
   } else if (command_line->HasSwitch(switches::kNoFirstRun)) {
-    first_run_state = CANCEL_FIRST_RUN;
+    internal::first_run_ = internal::FIRST_RUN_CANCEL;
   } else if (internal::GetFirstRunSentinelFilePath(&first_run_sentinel) &&
              !base::PathExists(first_run_sentinel)) {
-    first_run_state = IS_FIRST_RUN;
+    internal::first_run_ = internal::FIRST_RUN_TRUE;
   }
 
-  if (first_run_state == IS_FIRST_RUN || first_run_state == CANCEL_FIRST_RUN)
-    CreateSentinel();
+  return internal::first_run_ == internal::FIRST_RUN_TRUE;
+}
 
-  if (first_run_state == IS_FIRST_RUN) {
-    internal::first_run_ = internal::FIRST_RUN_TRUE;
-    return true;
-  } else {
-    internal::first_run_ = internal::FIRST_RUN_FALSE;
-    return false;
+void CreateSentinelIfNeeded() {
+  if (IsChromeFirstRun() ||
+      internal::first_run_ == internal::FIRST_RUN_CANCEL) {
+    internal::CreateSentinel();
   }
 }
 
-bool CreateSentinel() {
-  base::FilePath first_run_sentinel;
-  if (!internal::GetFirstRunSentinelFilePath(&first_run_sentinel))
-    return false;
-  return file_util::WriteFile(first_run_sentinel, "", 0) != -1;
-}
-
 std::string GetPingDelayPrefName() {
   return base::StringPrintf("%s.%s",
                             installer::master_preferences::kDistroDict,
                             installer::master_preferences::kDistroPingDelay);
 }
 
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterIntegerPref(
       GetPingDelayPrefName().c_str(),
       0,
@@ skipping 264 matching lines @@
   SetShouldDoPersonalDataManagerFirstRun();
 
   internal::DoPostImportPlatformSpecificTasks(profile);
 }
 
 uint16 auto_import_state() {
   return g_auto_import_state;
 }
 
 }  // namespace first_run