mojo: first take on removing mojo_main_{chromium,standalone}.

mojo/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 <stdio.h>
 
 #include "mojo/examples/echo/echo_service.mojom.h"
+#include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
+#include "mojo/public/cpp/application/application_runner.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 
 namespace mojo {
 namespace examples {
 
 class ResponsePrinter {
  public:
   void Run(const String& value) const {
     printf("Response: \"%s\"\n", value.get().c_str());
 
     RunLoop::current()->Quit();  // All done!
   }
 };
 
 class EchoClientDelegate : public ApplicationDelegate {
  public:
   virtual void Initialize(ApplicationImpl* app) MOJO_OVERRIDE {
     app->ConnectToService("mojo:mojo_echo_service", &echo_service_);
 
     echo_service_->EchoString("hello world", ResponsePrinter());
   }
 
  private:
   EchoServicePtr echo_service_;
 };
 
 }  // namespace examples
+}  // namespace mojo
 
-// static
-ApplicationDelegate* ApplicationDelegate::Create() {
-  return new examples::EchoClientDelegate();
+MojoResult MojoMain(MojoHandle shell_handle) {
+  mojo::ApplicationRunner runner(new mojo::examples::EchoClientDelegate);
+  return runner.Run(shell_handle);
 }
-
-}  // namespace mojo