Have mash_browser_tests recreate BackgroundServiceManager per test

chrome/test/base/chrome_test_launcher.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/test/base/chrome_test_launcher.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 11 matching lines @@
 #include "chrome/app/chrome_main_delegate.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/install_static/test/scoped_install_details.h"
 #include "chrome/test/base/chrome_test_suite.h"
 #include "components/crash/content/app/crashpad.h"
 #include "content/public/app/content_main.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/test/test_launcher.h"
 #include "content/public/test/test_utils.h"
+#include "services/service_manager/runner/common/switches.h"
 #include "ui/base/test/ui_controls.h"
 
 #if defined(OS_MACOSX)
 #include "chrome/browser/chrome_browser_application_mac.h"
 #endif  // defined(OS_MACOSX)
 
 #if defined(USE_AURA)
 #include "ui/aura/test/ui_controls_factory_aura.h"
 #include "ui/base/test/ui_controls_aura.h"
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
@@ skipping 10 matching lines @@
 #endif
 
 #if defined(OS_WIN)
 #include "chrome/app/chrome_crash_reporter_client_win.h"
 #endif
 
 ChromeTestSuiteRunner::ChromeTestSuiteRunner() {}
 ChromeTestSuiteRunner::~ChromeTestSuiteRunner() {}
 
 int ChromeTestSuiteRunner::RunTestSuite(int argc, char** argv) {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(service_manager::switches::kServicePipeToken))
+    content::GetContentMainParams()->env_mode = aura::Env::Mode::MUS;
+
   return ChromeTestSuite(argc, argv).Run();
 }
 
 ChromeTestLauncherDelegate::ChromeTestLauncherDelegate(
     ChromeTestSuiteRunner* runner)
     : runner_(runner) {}
 ChromeTestLauncherDelegate::~ChromeTestLauncherDelegate() {}
 
 int ChromeTestLauncherDelegate::RunTestSuite(int argc, char** argv) {
   return runner_->RunTestSuite(argc, argv);
@@ skipping 40 matching lines @@
 #if defined(OS_LINUX) || defined(OS_ANDROID) || defined(OS_WIN)
   // We leak this pointer intentionally. The crash client needs to outlive
   // all other code.
   ChromeCrashReporterClient* crash_client = new ChromeCrashReporterClient();
   ANNOTATE_LEAKING_OBJECT_PTR(crash_client);
   crash_reporter::SetCrashReporterClient(crash_client);
 #endif
 
   return content::LaunchTests(delegate, default_jobs, argc, argv);
 }