Reorder browser list on workspace switch

ui/display/desktop.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_DISPLAY_DESKTOP_H_
+#define UI_DISPLAY_DESKTOP_H_
+
+#include "base/lazy_instance.h"
+#include "base/observer_list.h"
+#include "ui/display/display_export.h"
+
+namespace display {
+
+class DesktopObserver;
+
+class DISPLAY_EXPORT Desktop {

[sky, 2016/07/01 22:18:33]

Sorry for not being clear. I was suggesting you have a Desktop::GetInstance()
function and add/remove observer functions on said object (not static).
Basically the same as in Screen. That way you have better object lifetime. 

+public:
+  static void AddObserver(DesktopObserver* observer);
+  static void RemoveObserver(DesktopObserver* observer);
+protected:
+ static base::LazyInstance<base::ObserverList<DesktopObserver>>::Leaky
+     desktop_observer_list_;
+};
+
+}  // namespace display
+
+#endif