Support chrome.windows extension API events for browserless Panels.

chrome/browser/extensions/window_controller_list_observer.h

Index: chrome/browser/extensions/window_controller_list_observer.h
diff --git a/chrome/browser/extensions/window_controller_list_observer.h b/chrome/browser/extensions/window_controller_list_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..daa1a8e90f66f0148f285c6eb65439a212a7320a
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+++ b/chrome/browser/extensions/window_controller_list_observer.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_WINDOW_CONTROLLER_LIST_OBSERVER_H_
+#define CHROME_BROWSER_EXTENSIONS_WINDOW_CONTROLLER_LIST_OBSERVER_H_
+
+namespace extensions {
+
+class WindowController;
+
+// Implementations must not change the contents of the WindowControllerList
+// inside any of these methods.
+class WindowControllerListObserver {
+  public:
+  // Called immediately after a window controller is added to the list
+  virtual void OnWindowControllerAdded(WindowController* window_controller) {}
+
+  // Called immediately after a window controller is removed from the list
+  virtual void OnWindowControllerRemoved(WindowController* window_controller) {}
+
+ protected:
+  virtual ~WindowControllerListObserver() {}
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_WINDOW_CONTROLLER_LIST_OBSERVER_H_