Revert r128507 "Revert r128436 "relanding: disabled workspace_window_resizer test. fixed access-aft…

ui/aura/monitor_change_observer_x11.h

+// Copyright (c) 2012 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_AURA_MONITOR_CHANGE_OBSERVER_H
+#define UI_AURA_MONITOR_CHANGE_OBSERVER_H
+#pragma once
+
+#include <X11/Xlib.h>
+
+// Xlib.h defines RootWindow.
+#undef RootWindow
+
+#include "base/basictypes.h"
+#include "ui/aura/aura_export.h"
+
+namespace aura {
+
+// An object that observes changes in monitor configuration and
+// update MonitorManagers.
+class AURA_EXPORT MonitorChangeObserverX11 {
+ public:
+  MonitorChangeObserverX11();
+  ~MonitorChangeObserverX11();
+
+  bool Dispatch(const XEvent* event);
+
+  // Reads monitor configurations from the system and notifies
+  // |monitor_manager_| about the change.
+  void NotifyMonitorChange();
+
+ private:
+  Display* xdisplay_;
+
+  ::Window x_root_window_;
+
+  int xrandr_event_base_;
+
+  DISALLOW_COPY_AND_ASSIGN(MonitorChangeObserverX11);
+};
+
+}  // namespace aura
+
+#endif  // UI_AURA_MONITOR_CHANGE_OBSERVER_H