Run the later parts of startup as UI thread tasks

content/shell/shell_browser_main.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 "content/shell/shell_browser_main.h"
 
 #include <iostream>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 109 matching lines @@
     CHECK(browser_context_path_for_layout_tests.CreateUniqueTempDir());
     CHECK(!browser_context_path_for_layout_tests.path().MaybeAsASCII().empty());
     CommandLine::ForCurrentProcess()->AppendSwitchASCII(
         switches::kContentShellDataPath,
         browser_context_path_for_layout_tests.path().MaybeAsASCII());
 
 #if defined(OS_ANDROID)
     content::EnsureInitializeForAndroidLayoutTests();
 #endif
   }
+  scoped_refptr<content::StartupTaskRunner> startup_task_runner =
+      make_scoped_refptr(new content::StartupTaskRunner(
+          content::StartupTaskRunner::IMMEDIATE, NULL));
 
-  int exit_code = main_runner->Initialize(parameters);
+  int exit_code = main_runner->Initialize(parameters, startup_task_runner);
   DCHECK_LT(exit_code, 0)
       << "BrowserMainRunner::Initialize failed in ShellBrowserMain";
 
   if (exit_code >= 0)
     return exit_code;
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kCheckLayoutTestSysDeps)) {
     base::MessageLoop::current()->PostTask(FROM_HERE,
                                            base::MessageLoop::QuitClosure());
@@ skipping 63 matching lines @@
 
 #if !defined(OS_ANDROID)
   if (!layout_test_mode)
     exit_code = main_runner->Run();
 
   main_runner->Shutdown();
 #endif
 
   return exit_code;
 }