Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used

mojo/shell/public/cpp/lib/application_runner.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 "mojo/shell/public/cpp/application_runner.h"
 
 #include "base/at_exit.h"
+#include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/process/launch.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 
 namespace mojo {
+namespace {
+
+void QuitMessageLoop() {
+  if (base::MessageLoop::current() &&
+      base::MessageLoop::current()->is_running()) {
+    base::MessageLoop::current()->QuitWhenIdle();

[sky, 2016/03/18 16:20:37]

If the messageloop is nested this quits the topmost runloop, which may not be
what you want. Instead create a RunLoop on 69 and call RunUntilIdle on it here.

+  }
+}
+
+}  // namespace
 
 int g_application_runner_argc;
 const char* const* g_application_runner_argv;
 
 ApplicationRunner::ApplicationRunner(ShellClient* client)
     : client_(scoped_ptr<ShellClient>(client)),
       message_loop_type_(base::MessageLoop::TYPE_DEFAULT),
       has_run_(false) {}
 
 ApplicationRunner::~ApplicationRunner() {}
@@ skipping 21 matching lines @@
   }
 
   {
     scoped_ptr<base::MessageLoop> loop;
     loop.reset(new base::MessageLoop(message_loop_type_));
 
     connection_.reset(new ShellConnection(
         client_.get(),
         MakeRequest<shell::mojom::ShellClient>(MakeScopedHandle(
             MessagePipeHandle(shell_client_request_handle)))));
+    connection_->set_connection_lost_closure(base::Bind(&QuitMessageLoop));
     loop->Run();
     // It's very common for the client to cache the app and terminate on errors.
     // If we don't delete the client before the app we run the risk of the
     // client having a stale reference to the app and trying to use it.
     // Note that we destruct the message loop first because that might trigger
     // connection error handlers and they might access objects created by the
     // client.
     loop.reset();
     client_.reset();
     connection_.reset();
@@ skipping 12 matching lines @@
 
 void ApplicationRunner::DestroyShellConnection() {
   connection_.reset();
 }
 
 void ApplicationRunner::Quit() {
   base::MessageLoop::current()->QuitWhenIdle();
 }
 
 }  // namespace mojo