Adds ability for ash_unittests to run in mushrome mode

mash/test/mash_test_suite.cc

 // Copyright 2016 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 "mash/test/mash_test_suite.h"
 
+#include "ash/public/cpp/config.h"
+#include "ash/test/ash_test_helper.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
 #include "base/path_service.h"
 #include "cc/output/context_provider.h"
 #include "cc/surfaces/frame_sink_id_allocator.h"
 #include "cc/surfaces/surface_manager.h"
 #include "ui/aura/env.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
@@ skipping 17 matching lines @@
 
   base::CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kOverrideUseSoftwareGLForTests);
 
   // Load ash mus strings and resources; not 'common' (Chrome) resources.
   base::FilePath resources;
   PathService::Get(base::DIR_MODULE, &resources);
   resources = resources.Append(FILE_PATH_LITERAL("ash_mus_resources.pak"));
   ui::ResourceBundle::InitSharedInstanceWithPakPath(resources);
 
+  ash::test::AshTestHelper::config_ = ash::Config::MASH;
+
   base::DiscardableMemoryAllocator::SetInstance(&discardable_memory_allocator_);
   env_ = aura::Env::CreateInstance(aura::Env::Mode::MUS);
 
   context_factory_ = base::MakeUnique<ui::FakeContextFactory>();
   env_->set_context_factory(context_factory_.get());
   env_->set_context_factory_private(nullptr);
 }
 
 void MashTestSuite::Shutdown() {
   env_.reset();
   ui::ResourceBundle::CleanupSharedInstance();
   base::TestSuite::Shutdown();
 }
 
 }  // namespace test
 }  // namespace mash