Mojo: Add an extremely skeletal mojo_shell_tests.

mojo/shell/shell_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/command_line.h"
+#include "base/logging.h"
+#include "base/test/launcher/unit_test_launcher.h"
+#include "base/test/test_suite.h"
+#include "mojo/shell/child_process.h"
+#include "mojo/shell/switches.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+int main(int argc, char** argv) {
+  base::CommandLine::Init(argc, argv);
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(switches::kChildProcessType)) {
+    scoped_ptr<mojo::shell::ChildProcess> child_process =
+        mojo::shell::ChildProcess::Create(command_line);
+    CHECK(child_process);
+    child_process->Main();
+    return 0;
+  }
+
+  base::TestSuite test_suite(argc, argv);
+  return base::LaunchUnitTests(
+      argc, argv, base::Bind(&base::TestSuite::Run,
+                             base::Unretained(&test_suite)));
+}