Mojo: more idiomatic C++ bindings

mojo/examples/dbus_echo/dbus_echo_app.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 <string>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "mojo/public/cpp/application/application.h"
-#include "mojo/public/cpp/bindings/allocation_scope.h"
 #include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/system/core.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/public/interfaces/service_provider/service_provider.mojom.h"
 #include "mojo/services/dbus_echo/echo.mojom.h"
 
 namespace mojo {
 namespace examples {
 
 class DBusEchoApp : public Application {
  public:
   DBusEchoApp() {}
   virtual ~DBusEchoApp() {}
 
   virtual void Initialize() MOJO_OVERRIDE {
     ConnectTo("dbus:org.chromium.EchoService/org/chromium/MojoImpl",
               &echo_service_);
 
-    AllocationScope scope;
-    echo_service_->Echo("who", base::Bind(&DBusEchoApp::OnEcho,
-                                          base::Unretained(this)));
+    echo_service_->Echo(
+        String::From("who"),
+        base::Bind(&DBusEchoApp::OnEcho, base::Unretained(this)));
   }
 
  private:
-  void OnEcho(const String& echoed) {
-    LOG(INFO) << "echo'd " << echoed.To<std::string>();
+  void OnEcho(String echoed) {
+    LOG(INFO) << "echo'd " << echoed;
   }
 
   EchoServicePtr echo_service_;
 
   DISALLOW_COPY_AND_ASSIGN(DBusEchoApp);
 };
 
 }  // namespace examples
 
 // static
 Application* Application::Create() {
   return new examples::DBusEchoApp();
 }
 
 }  // namespace mojo