Adds AcceleratorManagerDelegate

ui/base/accelerators/accelerator_manager_delegate.h

+// 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.
+
+#ifndef UI_BASE_ACCELERATORS_ACCELERATOR_MANAGER_DELEGATE_H_
+#define UI_BASE_ACCELERATORS_ACCELERATOR_MANAGER_DELEGATE_H_
+
+#include "ui/base/ui_base_export.h"
+
+namespace ui {
+
+class Accelerator;
+
+class UI_BASE_EXPORT AcceleratorManagerDelegate {
+ public:
+  // Called the first time a target is registered for |accelerator|. This is
+  // only called the first time a target is registered for a unique accelerator.
+  // For example, if Register() is called twice with the same accelerator
+  // this is called only for the first call.
+  virtual void OnAcceleratorRegistered(const Accelerator& accelerator) = 0;
+
+  // Called when there no more targets are registered for |accelerator|.
+  virtual void OnAcceleratorUnregistered(const Accelerator& accelerator) = 0;
+
+ protected:
+  virtual ~AcceleratorManagerDelegate() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_ACCELERATORS_ACCELERATOR_MANAGER_DELEGATE_H_