Reorder browser list on workspace switch

ui/display/desktop.cc

+// 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.
+
+#include "ui/display/desktop.h"
+
+namespace display {
+
+//static
+base::LazyInstance<base::ObserverList<DesktopObserver>>::Leaky
+    Desktop::desktop_observer_list_;
+
+void Desktop::AddObserver(DesktopObserver* observer) {
+  desktop_observer_list_.Get().AddObserver(observer);
+}
+
+void Desktop::RemoveObserver(DesktopObserver* observer) {
+  desktop_observer_list_.Get().RemoveObserver(observer);
+}
+
+}  // namespace display