Reorder browser list on workspace switch

ui/display/desktop_observer.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_OBSERVER_H_
+#define UI_DISPLAY_DESKTOP_OBSERVER_H_
+
+#include <string>
+
+#include "ui/display/display_export.h"
+
+namespace display {
+
+// Observers for desktop configuration changes.
+class DISPLAY_EXPORT DesktopObserver {
+ public:
+  // Called when the (platform-specific) workspace ID changes to
+  // |new_workspace|.
+  virtual void OnWorkspaceChanged(const std::string& new_workspace) = 0;
+
+ protected:
+  virtual ~DesktopObserver();
+};
+
+}  // namespace display
+
+#endif  // UI_DISPLAY_DESKTOP_OBSERVER_H_