Upstream Chrome on iOS source code [4/11].

ios/chrome/browser/ui/bookmarks/undo_manager_bridge_observer.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_BOOKMARKS_UNDO_MANAGER_BRIDGE_OBSERVER_H_
+#define IOS_CHROME_BROWSER_UI_BOOKMARKS_UNDO_MANAGER_BRIDGE_OBSERVER_H_
+
+#include "base/compiler_specific.h"
+#include "components/undo/undo_manager_observer.h"
+
+// The ObjC translations of the C++ observer callbacks are defined here.
+@protocol UndoManagerBridgeObserver
+// Invoked when the internal state of the undo manager has changed.
+- (void)undoManagerChanged;
+@end
+
+namespace bookmarks {
+// A bridge that translates UndoManagerObserver C++ callbacks into ObjC
+// callbacks.
+class UndoManagerBridge : public UndoManagerObserver {
+ public:
+  explicit UndoManagerBridge(id<UndoManagerBridgeObserver> observer);
+  ~UndoManagerBridge() override{};
+
+ private:
+  void OnUndoManagerStateChange() override;
+  id<UndoManagerBridgeObserver> observer_;
+};
+}  // namespace bookmarks
+
+#endif  // IOS_CHROME_BROWSER_UI_BOOKMARKS_UNDO_MANAGER_BRIDGE_OBSERVER_H_