Reorder browser list on workspace switch

ui/display/desktop_observer.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_observer.h"
+
+#include "base/lazy_instance.h"
+#include "base/observer_list.h"
+
+namespace display {
+
+namespace desktop {
+
+namespace {
+
+base::LazyInstance<base::ObserverList<DesktopObserver>>::Leaky
+    g_desktop_observer_list;
+
+}  // anonymous namespace
+
+DesktopObserver::~DesktopObserver() {}
+
+void AddObserver(DesktopObserver* observer) {
+  g_desktop_observer_list.Get().AddObserver(observer);
+}
+
+void RemoveObserver(DesktopObserver* observer) {
+  g_desktop_observer_list.Get().RemoveObserver(observer);
+}
+
+void OnWorkspaceChanged(const std::string& new_workspace) {
+  FOR_EACH_OBSERVER(DesktopObserver, g_desktop_observer_list.Get(),
+                    OnWorkspaceChanged(new_workspace));
+}
+
+}  // namespace desktop
+
+}  // namespace display