Mandoline: Introduce ApplicationConnection::CloseConnection

mojo/application/public/cpp/lib/application_connection.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/application/public/cpp/application_connection.h"
 
+#include "base/logging.h"
+
 namespace mojo {
 
+ApplicationConnection::ApplicationConnection() : connection_closed_(false) {
+}
+
+void ApplicationConnection::CloseConnection() {
+  if (connection_closed_)
+    return;
+  OnCloseConnection();
+  connection_closed_ = true;
+  delete this;
+}
+
 ApplicationConnection::~ApplicationConnection() {
+  // If this DCHECK fails then something has tried to delete this object without
+  // calling CloseConnection.
+  DCHECK(connection_closed_);
 }
 
 }  // namespace mojo