Add a Mojo example apptest that runs in mojo_shell.

mojo/examples/test/example_service_impl.cc

Index: mojo/examples/test/example_service_impl.cc
diff --git a/mojo/examples/test/example_service_impl.cc b/mojo/examples/test/example_service_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e4c0c76de3ba1d9a6fc9be4b9ed1595561354385
--- /dev/null
+++ b/mojo/examples/test/example_service_impl.cc
@@ -0,0 +1,31 @@
+// 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 "mojo/examples/test/example_service_impl.h"
+
+#include "base/logging.h"
+#include "mojo/public/cpp/utility/run_loop.h"
+
+namespace mojo {
+
+ExampleServiceImpl::ExampleServiceImpl(ApplicationConnection* connection,
+                                       ApplicationDelegate* delegate) {
+}
+
+ExampleServiceImpl::~ExampleServiceImpl() {}
+
+void ExampleServiceImpl::Echo(const String& to_echo,
+                              const Callback<void(String)>& callback) {
+  LOG(ERROR) << "MSW: ExampleServiceImpl::Echo: " << to_echo.get();
+  //callback.Run(to_echo);
+  RunLoop::current()->Quit();

[Ben Goodger (Google), 2014/07/18 20:02:52]

What are you trying to achieve here?

[msw, 2014/07/21 18:58:22]

The process continues running after executing the tests (need to Ctrl+C in the
commandline); RunLoop::Quit calls don't help, so I removed them. Any tips?

[Ben Goodger (Google), 2014/07/21 20:02:38]

You would not be able to add code like this to a production service you were
testing. Instead I think you need the ability to end the service. I think this
code is in flux currently. Dave's code attempts to manage service lifetimes
automagically, and to me that implies that when the total connection count of an
application's services drops to zero, that that application thread would exit,
but he says that's not currently how it works.

[tim (not reviewing), 2014/07/23 01:16:09]

I think that the way it is written now, ExampleServiceImpl is an example of a
"well behaved" app in that it quits itself when done. Kind of like
examples/wget.cc.  Ideally, most apps would have a condition they would meet and
eventually quit their run loops.

For cases where they do not, we need to have other ways of killing them
especially for tests.  This is what I am working on currently; see
https://docs.google.com/a/chromium.org/document/d/1tKZw3cnnGEuoOD1gYLmPQtqYHN...

But for getting started here, writing a well-defined app like this that quits
itself is probably OK?

+}
+
+void ExampleServiceImpl::Ping(uint16_t ping_value) {
+  LOG(ERROR) << "MSW: ExampleServiceImpl::Ping: " << ping_value;
+  client()->Pong(ping_value);
+  RunLoop::current()->Quit();

[Ben Goodger (Google), 2014/07/18 20:02:52]

again not sure why you're quitting the runloop here.

[msw, 2014/07/21 18:58:22]

ditto; removed.

+}
+
+}  // namespace mojo