Add an even simpler standalone example.

This example is like the echo examples, but has no dependencies outside
of //mojo/public (in particular, no //base dependency).

R=vardhan@google.com

Review URL: https://codereview.chromium.org/1702103002 .
diff --git a/examples/BUILD.gn b/examples/BUILD.gn
index 2eb75dc..1f8da31 100644
--- a/examples/BUILD.gn
+++ b/examples/BUILD.gn
@@ -18,6 +18,7 @@
     "//examples/echo",
     "//examples/echo_terminal",
     "//examples/forwarding_content_handler",
+    "//examples/hello_mojo",
     "//examples/http_handler",
     "//examples/indirect_service",
     "//examples/native_run_app",
diff --git a/examples/hello_mojo/BUILD.gn b/examples/hello_mojo/BUILD.gn
new file mode 100644
index 0000000..1c909a2
--- /dev/null
+++ b/examples/hello_mojo/BUILD.gn
@@ -0,0 +1,49 @@
+# Copyright 2016 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.
+
+import("//mojo/public/mojo_application.gni")
+import("//mojo/public/tools/bindings/mojom.gni")
+
+group("hello_mojo") {
+  deps = [
+    ":hello_mojo_client",
+    ":hello_mojo_server",
+  ]
+}
+
+mojo_native_application("hello_mojo_client") {
+  deps = [
+    ":hello_mojo_interface",
+    "//mojo/public/c/system",
+    "//mojo/public/cpp/application:standalone",
+    "//mojo/public/cpp/bindings",
+    "//mojo/public/cpp/system",
+    "//mojo/public/cpp/utility",
+  ]
+
+  sources = [
+    "hello_mojo_client.cc",
+  ]
+}
+
+mojo_native_application("hello_mojo_server") {
+  deps = [
+    ":hello_mojo_interface",
+    "//mojo/public/c/system",
+    "//mojo/public/cpp/application:standalone",
+    "//mojo/public/cpp/bindings",
+    "//mojo/public/cpp/system",
+    "//mojo/public/cpp/utility",
+  ]
+
+  sources = [
+    "hello_mojo_server.cc",
+  ]
+}
+
+mojom("hello_mojo_interface") {
+  sources = [
+    "hello_mojo.mojom",
+  ]
+}
diff --git a/examples/hello_mojo/README.md b/examples/hello_mojo/README.md
new file mode 100644
index 0000000..80fb48a
--- /dev/null
+++ b/examples/hello_mojo/README.md
@@ -0,0 +1,17 @@
+# Hello Mojo example applications
+
+`hello_mojo_server` and `hello_mojo_client` are like the [echo
+examples](../echo), but a bit more minimal and with no dependencies outside of
+the [Mojo public C/C++ SDK](../../mojo/public).
+
+## Running
+
+For example, for a Linux debug build, from the command line:
+
+    $ out/Debug/mojo_shell mojo:hello_mojo_client
+
+## See also
+
+* [echo examples](../echo)
+* [Mojo public C SDK](../../mojo/public/c)
+* [Mojo public C++ SDK](../../mojo/public/cpp)
diff --git a/examples/hello_mojo/hello_mojo.mojom b/examples/hello_mojo/hello_mojo.mojom
new file mode 100644
index 0000000..7c02852
--- /dev/null
+++ b/examples/hello_mojo/hello_mojo.mojom
@@ -0,0 +1,10 @@
+// Copyright 2016 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.
+
+module examples;
+
+[ServiceName="examples.HelloMojo"]
+interface HelloMojo {
+  Say(string request) => (string response);
+};
diff --git a/examples/hello_mojo/hello_mojo_client.cc b/examples/hello_mojo/hello_mojo_client.cc
new file mode 100644
index 0000000..ba12db1
--- /dev/null
+++ b/examples/hello_mojo/hello_mojo_client.cc
@@ -0,0 +1,52 @@
+// Copyright 2016 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 <memory>
+#include <string>
+
+#include "examples/hello_mojo/hello_mojo.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/system/macros.h"
+#include "mojo/public/cpp/utility/run_loop.h"
+
+using examples::HelloMojoPtr;
+
+namespace {
+
+class HelloMojoClientApp : public mojo::ApplicationDelegate {
+ public:
+  HelloMojoClientApp() {}
+  ~HelloMojoClientApp() override {}
+
+  void Initialize(mojo::ApplicationImpl* application) override {
+    application->ConnectToService("mojo:hello_mojo_server", &hello_mojo_);
+
+    DoIt("hello");
+    DoIt("goodbye");
+  }
+
+ private:
+  void DoIt(const std::string& request) {
+    hello_mojo_->Say(request, [request](const mojo::String& response) {
+      printf("%s --> %s\n", request.c_str(), response.get().c_str());
+    });
+  }
+
+  HelloMojoPtr hello_mojo_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(HelloMojoClientApp);
+};
+
+}  // namespace
+
+MojoResult MojoMain(MojoHandle application_request) {
+  return mojo::ApplicationRunner(std::unique_ptr<mojo::ApplicationDelegate>(
+                                     new HelloMojoClientApp()))
+      .Run(application_request);
+}
diff --git a/examples/hello_mojo/hello_mojo_server.cc b/examples/hello_mojo/hello_mojo_server.cc
new file mode 100644
index 0000000..08efddd
--- /dev/null
+++ b/examples/hello_mojo/hello_mojo_server.cc
@@ -0,0 +1,70 @@
+// Copyright 2016 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 <memory>
+#include <string>
+#include <utility>
+
+#include "examples/hello_mojo/hello_mojo.mojom.h"
+#include "mojo/public/c/system/main.h"
+#include "mojo/public/cpp/application/application_connection.h"
+#include "mojo/public/cpp/application/application_delegate.h"
+#include "mojo/public/cpp/application/application_runner.h"
+#include "mojo/public/cpp/application/interface_factory.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "mojo/public/cpp/system/macros.h"
+
+using examples::HelloMojo;
+
+namespace {
+
+class HelloMojoImpl : public HelloMojo {
+ public:
+  explicit HelloMojoImpl(mojo::InterfaceRequest<HelloMojo> hello_mojo_request)
+      : strong_binding_(this, std::move(hello_mojo_request)) {}
+  ~HelloMojoImpl() override {}
+
+  // |examples::HelloMojo| implementation:
+  void Say(const mojo::String& request,
+           const mojo::Callback<void(mojo::String)>& callback) override {
+    callback.Run((request.get() == "hello") ? "mojo" : "WAT");
+  }
+
+ private:
+  mojo::StrongBinding<HelloMojo> strong_binding_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(HelloMojoImpl);
+};
+
+class HelloMojoServerApp : public mojo::ApplicationDelegate,
+                           public mojo::InterfaceFactory<HelloMojo> {
+ public:
+  HelloMojoServerApp() {}
+  ~HelloMojoServerApp() override {}
+
+  // |mojo::ApplicationDelegate| implementation:
+  bool ConfigureIncomingConnection(
+      mojo::ApplicationConnection* application_connection) override {
+    application_connection->AddService<HelloMojo>(this);
+    return true;
+  }
+
+  // |mojo::InterfaceFactory<HelloMojo>| implementation:
+  void Create(mojo::ApplicationConnection* application_connection,
+              mojo::InterfaceRequest<HelloMojo> hello_mojo_request) override {
+    new HelloMojoImpl(std::move(hello_mojo_request));  // Owns itself.
+  }
+
+ private:
+  MOJO_DISALLOW_COPY_AND_ASSIGN(HelloMojoServerApp);
+};
+
+}  // namespace
+
+MojoResult MojoMain(MojoHandle application_request) {
+  return mojo::ApplicationRunner(std::unique_ptr<mojo::ApplicationDelegate>(
+                                     new HelloMojoServerApp()))
+      .Run(application_request);
+}