Get rid of {Run,Terminate}MainApplication(), and more ApplicationDelegate conversion.

examples/echo/echo_client.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/logging.h"
 #include "examples/echo/echo.mojom.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_impl_base.h"
 #include "mojo/public/cpp/application/connect.h"
 #include "mojo/public/cpp/application/run_application.h"
@@ skipping 20 matching lines @@
 
  private:
   EchoPtr echo_;
 };
 
 }  // namespace examples
 }  // namespace mojo
 
 MojoResult MojoMain(MojoHandle application_request) {
   mojo::examples::EchoClientApp echo_client_app;
-  return mojo::RunMainApplication(application_request, &echo_client_app);
+  return mojo::RunApplication(application_request, &echo_client_app);
 }