Fix possible deadlock during shutdown by not using the FILE thread.

chrome/browser/extensions/extension_service_test_base.cc

 // Copyright 2014 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/extensions/extension_service_test_base.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
@@ skipping 73 matching lines @@
       service_(NULL),
       testing_local_state_(TestingBrowserProcess::GetGlobal()),
       did_reset_thread_bundle_(false),
       registry_(NULL) {
   base::FilePath test_data_dir;
   if (!PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir)) {
     ADD_FAILURE();
     return;
   }
   data_dir_ = test_data_dir.AppendASCII("extensions");
+  base::CommandLine::ForCurrentProcess()->AppendSwitch("mojo-local-storage");
 }
 
 ExtensionServiceTestBase::~ExtensionServiceTestBase() {
   // Parts of destruction have to happen on an IO thread, so if the thread
   // bundle is reset, we need to change it back.
   if (did_reset_thread_bundle_)
     ResetThreadBundle(kThreadOptions);
 
   // Why? Because |profile_| has to be destroyed before |at_exit_manager_|, but
   // is declared above it in the class definition since it's protected.
@@ skipping 231 matching lines @@
 
   service_->RegisterInstallGate(ExtensionPrefs::DELAY_REASON_WAIT_FOR_IMPORTS,
                                 service_->shared_module_service());
 
 #if defined(OS_CHROMEOS)
   InstallLimiter::Get(profile_.get())->DisableForTest();
 #endif
 }
 
 }  // namespace extensions