MacViews: Implement event monitoring for a specific window

ui/views/event_monitor.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 UI_VIEWS_EVENT_MONITOR_H_
 #define UI_VIEWS_EVENT_MONITOR_H_
 
 #include "ui/gfx/geometry/point.h"
+#include "ui/gfx/native_widget_types.h"
 #include "ui/views/views_export.h"
 
 namespace ui {
 class EventHandler;
 }
 
 namespace views {
 
 // RAII-style class that forwards events posted to the application to
 // |event_handler| before they are dispatched.
 class VIEWS_EXPORT EventMonitor {
  public:
   virtual ~EventMonitor() {}
 
   static EventMonitor* Create(ui::EventHandler* event_handler);
+  static EventMonitor* Create(ui::EventHandler* event_handler,
+                              gfx::NativeWindow target_window);
 
   // Returns the last mouse location seen in a mouse event in screen
   // coordinates.
   static gfx::Point GetLastMouseLocation();
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_EVENT_MONITOR_H_