Mojo C++ bindings: introduce public associated-interface-related types.

mojo/public/cpp/bindings/lib/associated_group.cc

+// Copyright 2015 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/public/cpp/bindings/associated_group.h"
+
+#include "mojo/public/cpp/bindings/lib/multiplex_router.h"
+
+namespace mojo {
+
+AssociatedGroup::AssociatedGroup() {}
+
+AssociatedGroup::AssociatedGroup(const AssociatedGroup& other)
+    : router_(other.router_) {}
+
+AssociatedGroup::~AssociatedGroup() {}
+
+AssociatedGroup& AssociatedGroup::operator=(const AssociatedGroup& other) {
+  if (this == &other)
+    return *this;
+
+  router_ = other.router_;
+  return *this;
+}
+
+void AssociatedGroup::CreateEndpointHandlePair(
+    internal::ScopedInterfaceEndpointHandle* local_endpoint,
+    internal::ScopedInterfaceEndpointHandle* remote_endpoint) {
+  if (!router_)
+    return;
+
+  router_->CreateEndpointHandlePair(local_endpoint, remote_endpoint);
+}
+
+}  // namespace mojo