Creates BackgroundShell and uses it in test

ui/views/run_all_unittests.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 "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/path_service.h"
 #include "base/test/launcher/unit_test_launcher.h"
 #include "base/test/test_suite.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/gl/test/gl_surface_test_support.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/env.h"
 #endif
 
+namespace views {
+
 class ViewTestSuite : public base::TestSuite {
  public:
   ViewTestSuite(int argc, char** argv) : base::TestSuite(argc, argv) {}
 
  protected:
   void Initialize() override {
     base::TestSuite::Initialize();
     gfx::GLSurfaceTestSupport::InitializeOneOff();
     ui::RegisterPathProvider();
 
@@ skipping 10 matching lines @@
     aura::Env::DeleteInstance();
 #endif
     ui::ResourceBundle::CleanupSharedInstance();
     base::TestSuite::Shutdown();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ViewTestSuite);
 };
 
-int main(int argc, char** argv) {
+int RunAllUnittests(int argc, char** argv) {
   ViewTestSuite test_suite(argc, argv);
 
   return base::LaunchUnitTests(
       argc, argv, base::Bind(&ViewTestSuite::Run,
                              base::Unretained(&test_suite)));
 }
+
+}  // namespace views