Made it possible to tell whether an extension is being installed or updated.

chrome/browser/extensions/event_router.cc

 // 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.
 
 #include "chrome/browser/extensions/event_router.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 640 matching lines @@
     case chrome::NOTIFICATION_EXTENSION_UNLOADED: {
       // Remove all registered lazy listeners from our cache.
       UnloadedExtensionInfo* unloaded =
           content::Details<UnloadedExtensionInfo>(details).ptr();
       listeners_.RemoveLazyListenersForExtension(unloaded->extension->id());
       break;
     }
     case chrome::NOTIFICATION_EXTENSION_INSTALLED: {
       // Dispatch the onInstalled event.
       const Extension* extension =
-          content::Details<const Extension>(details).ptr();
+          content::Details<const InstalledExtensionInfo>(details)->extension;
 
       // Get the previous version, if this is an upgrade.
       ExtensionService* service =
           ExtensionSystem::Get(profile_)->extension_service();
       const Extension* old = service->GetExtensionById(extension->id(), true);
       Version old_version;
       if (old)
         old_version = *old->version();
 
       MessageLoop::current()->PostTask(FROM_HERE,
@@ skipping 53 matching lines @@
   copy->will_dispatch_callback = will_dispatch_callback;
   return copy;
 }
 
 EventListenerInfo::EventListenerInfo(const std::string& event_name,
                                      const std::string& extension_id)
     : event_name(event_name),
       extension_id(extension_id) {}
 
 }  // namespace extensions