Mojo C++ Bindings: Extract AssociatedGroupController from MultiplexRouter

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

+// 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 "mojo/public/cpp/bindings/associated_group_controller.h"
+
+#include "mojo/public/cpp/bindings/associated_group.h"
+
+namespace mojo {
+
+AssociatedGroupController::AssociatedGroupController(
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    : base::RefCountedDeleteOnMessageLoop<AssociatedGroupController>(
+          task_runner) {}
+
+AssociatedGroupController::~AssociatedGroupController() {}
+
+std::unique_ptr<AssociatedGroup>
+AssociatedGroupController::CreateAssociatedGroup() {
+  std::unique_ptr<AssociatedGroup> group(new AssociatedGroup);
+  group->controller_ = this;
+  return group;
+}
+
+ScopedInterfaceEndpointHandle
+AssociatedGroupController::CreateScopedInterfaceEndpointHandle(
+    InterfaceId id,
+    bool is_local) {
+  return ScopedInterfaceEndpointHandle(id, is_local, this);
+}
+
+}  // namespace mojo