refactor: rename the atom directory to shell

shell/browser/window_list_observer.h

@@ -0,0 +1,34 @@
+// Copyright (c) 2013 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_WINDOW_LIST_OBSERVER_H_
+#define ATOM_BROWSER_WINDOW_LIST_OBSERVER_H_
+
+#include "base/observer_list_types.h"
+
+namespace atom {
+
+class NativeWindow;
+
+class WindowListObserver : public base::CheckedObserver {
+ public:
+  // Called immediately after a window is added to the list.
+  virtual void OnWindowAdded(NativeWindow* window) {}
+
+  // Called immediately after a window is removed from the list.
+  virtual void OnWindowRemoved(NativeWindow* window) {}
+
+  // Called when a window close is cancelled by beforeunload handler.
+  virtual void OnWindowCloseCancelled(NativeWindow* window) {}
+
+  // Called immediately after all windows are closed.
+  virtual void OnWindowAllClosed() {}
+
+ protected:
+  ~WindowListObserver() override {}
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_WINDOW_LIST_OBSERVER_H_