Disallow display of multiple experimental.extension.popup(...) windows

chrome/common/notification_type.h

 // Copyright (c) 2009 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_COMMON_NOTIFICATION_TYPE_H_
 #define CHROME_COMMON_NOTIFICATION_TYPE_H_
 
 // This file describes various types used to describe and filter notifications
 // that pass through the NotificationService.
 //
@@ skipping 777 matching lines @@
     // during browser shutdown.
     EXTENSION_PROCESS_TERMINATED,
 
     // Sent when the contents or order of toolstrips in the shelf model change.
     EXTENSION_SHELF_MODEL_CHANGED,
 
     // Sent when a background page is ready so other components can load.
     EXTENSION_BACKGROUND_PAGE_READY,
 
     // Sent when a pop-up extension view is ready, so that notification may
-    // be sent to pending callbacks.
+    // be sent to pending callbacks.  Note that this notification is sent
+    // after all onload callbacks have been invoked in the main frame.
+    // The details is the ExtensionHost* hosted within the popup, and the source
+    // is a Profile*.
     EXTENSION_POPUP_VIEW_READY,
 
     // Sent when a browser action's state has changed. The source is the
     // ExtensionAction* that changed.  There are no details.
     EXTENSION_BROWSER_ACTION_UPDATED,
 
     // Sent when the count of page actions has changed. Note that some of them
     // may not apply to the current page. The source is a LocationBar*. There
     // are no details.
     EXTENSION_PAGE_ACTION_COUNT_CHANGED,
@@ skipping 183 matching lines @@
 };
 
 inline bool operator==(NotificationType::Type a, NotificationType b) {
   return a == b.value;
 }
 inline bool operator!=(NotificationType::Type a, NotificationType b) {
   return a != b.value;
 }
 
 #endif  // CHROME_COMMON_NOTIFICATION_TYPE_H_