Move shell service to toplevel shell namespace

mash/wm/window_manager_unittest.cc

 // Copyright 2015 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 <stdint.h>
 
 #include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 13 matching lines @@
   ~WindowTreeDelegateImpl() override {}
 
  private:
   // mus::WindowTreeDelegate:
   void OnEmbed(mus::Window* root) override {}
   void OnConnectionLost(mus::WindowTreeConnection* connection) override {}
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeDelegateImpl);
 };
 
-class WindowManagerTest : public mojo::test::ShellTest {
+class WindowManagerTest : public shell::test::ShellTest {
  public:
-  WindowManagerTest() : mojo::test::ShellTest("exe:mash_unittests") {}
+  WindowManagerTest() : shell::test::ShellTest("exe:mash_unittests") {}
   ~WindowManagerTest() override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WindowManagerTest);
 };
 
 void OnEmbed(bool success) {
   ASSERT_TRUE(success);
 }
 
@@ skipping 20 matching lines @@
   child_window->Embed(std::move(tree_client), base::Bind(&OnEmbed));
   std::unique_ptr<mus::WindowTreeConnection> child_connection(
       mus::WindowTreeConnection::Create(
           &window_tree_delegate, std::move(tree_client_request),
           mus::WindowTreeConnection::CreateType::WAIT_FOR_EMBED));
   ASSERT_TRUE(!child_connection->GetRoots().empty());
 }
 
 }  // namespace wm
 }  // namespace mash