Lands http://codereview.chromium.org/2928005/ for Dill:

ui/base/models/menu_model_delegate.h

+// Copyright (c) 2010 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_MODELS_MENU_MODEL_DELEGATE_H_
+#define UI_BASE_MODELS_MENU_MODEL_DELEGATE_H_
+#pragma once
+
+namespace ui {
+
+class MenuModelDelegate {
+ public:
+  // Invoked when an icon has been loaded from history.
+  virtual void OnIconChanged(int index) = 0;
+
+ protected:
+  virtual ~MenuModelDelegate() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_MODELS_MENU_MODEL_DELEGATE_H_