Remove redundant echo.mojom, verify non-nullables in echo_service.mojom

mojo/services/dbus_echo/dbus_echo_service.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/at_exit.h"
-#include "base/callback.h"
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop.h"
-#include "base/run_loop.h"
-#include "mojo/dbus/dbus_external_service.h"
-#include "mojo/embedder/channel_init.h"
-#include "mojo/embedder/embedder.h"
-#include "mojo/embedder/simple_platform_support.h"
-#include "mojo/public/cpp/environment/environment.h"
-#include "mojo/services/dbus_echo/echo.mojom.h"
-
-namespace {
-class EchoServiceImpl : public mojo::InterfaceImpl<mojo::EchoService> {
- public:
-  EchoServiceImpl() {}
-  virtual ~EchoServiceImpl() {}
-
- protected:
-  virtual void Echo(
-      const mojo::String& in_to_echo,
-      const mojo::Callback<void(mojo::String)>& callback) OVERRIDE {
-    DVLOG(1) << "Asked to echo " << in_to_echo;
-    callback.Run(in_to_echo);
-  }
-};
-
-const char kServiceName[] = "org.chromium.EchoService";
-}  // anonymous namespace
-
-int main(int argc, char** argv) {
-  base::AtExitManager exit_manager;
-  base::CommandLine::Init(argc, argv);
-
-  logging::LoggingSettings settings;
-  settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
-  logging::InitLogging(settings);
-  logging::SetLogItems(false,    // Process ID
-                       false,    // Thread ID
-                       false,    // Timestamp
-                       false);   // Tick count
-
-  mojo::embedder::Init(scoped_ptr<mojo::embedder::PlatformSupport>(
-      new mojo::embedder::SimplePlatformSupport()));
-
-  base::MessageLoopForIO message_loop;
-  base::RunLoop run_loop;
-
-  mojo::DBusExternalService<EchoServiceImpl> echo_service(kServiceName);
-  echo_service.Start();
-
-  run_loop.Run();
-  return 0;
-}