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

chrome/browser/ui/gtk/first_run_dialog.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/ui/gtk/first_run_dialog.h"
 
 #include <string>
 #include <vector>
 
 #include "base/i18n/rtl.h"
@@ skipping 142 matching lines @@
 
   g_signal_connect(dialog_, "response",
                    G_CALLBACK(OnResponseDialogThunk), this);
   gtk_widget_show_all(dialog_);
 }
 
 void FirstRunDialog::OnResponseDialog(GtkWidget* widget, int response) {
   if (dialog_)
     gtk_widget_hide_all(dialog_);
 
-  // Mark that first run has ran.
-  first_run::CreateSentinel();
-
   // Check if user has opted into reporting.
   if (report_crashes_ &&
       gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(report_crashes_))) {
     if (GoogleUpdateSettings::SetCollectStatsConsent(true))
       InitCrashReporter();
   } else {
     GoogleUpdateSettings::SetCollectStatsConsent(false);
   }
 
   // If selected set as default browser.
@@ skipping 10 matching lines @@
 }
 
 void FirstRunDialog::FirstRunDone() {
   first_run::SetShouldShowWelcomePage();
 
   if (dialog_)
     gtk_widget_destroy(dialog_);
   base::MessageLoop::current()->Quit();
   delete this;
 }