Move //mojo/shell to //shell

mojo/shell/external_application_test_main.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 "base/bind.h"
-#include "base/test/launcher/unit_test_launcher.h"
-#include "base/test/test_suite.h"
-#include "mojo/edk/embedder/embedder.h"
-#include "mojo/edk/embedder/simple_platform_support.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-int main(int argc, char** argv) {
-  mojo::embedder::Init(scoped_ptr<mojo::embedder::PlatformSupport>(
-      new mojo::embedder::SimplePlatformSupport()));
-
-  base::TestSuite test_suite(argc, argv);
-  return base::LaunchUnitTests(
-      argc,
-      argv,
-      base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));
-}