Add "UninstallReason" parameter to ExtensionRegistryObserver::OnExtensionUninstalled.

chrome/browser/chrome_notification_types.h

Index: chrome/browser/chrome_notification_types.h
diff --git a/chrome/browser/chrome_notification_types.h b/chrome/browser/chrome_notification_types.h
index eddec14051a48e281a4b31b03c3b30772d823fc5..e8585f02b9c721b6eb392c49bd83d0e6c363daa4 100644
--- a/chrome/browser/chrome_notification_types.h
+++ b/chrome/browser/chrome_notification_types.h
@@ -418,8 +418,8 @@ enum NotificationType {
 
   // DEPRECATED: Use ExtensionRegistry::AddObserver instead.
   //
-  // Sent when an extension has been uninstalled. The details are an Extension,
-  // and the source is a Profile.
+  // Sent when an extension has been uninstalled. The details are an
+  // UnloadedExtensionInfo, and the source is a Profile.

[Devlin, 2014/07/16 20:05:43]

Is there a reason we need to include the type with the notification?  It doesn't
look like any of the current clients need it...

[rpaquay, 2014/07/16 21:16:45]

The next CL will have a change to use "reason" from within one of the observers
(in extensions/browser/api/runtime_api.cc).

That said, there is a typo in the comment above (should be
"UninstalledExtensionInfo") that I am fixing in the next patchset.

[Devlin, 2014/07/16 21:29:38]

Hmm... I'm concerned about updating a deprecated notification.  It'll just make
the transition to ExtensionRegistryObserver that much harder.  Perhaps it would
be better to modify ExtensionRegistryObserver::OnExtensionUninstalled, and
update RuntimeAPI to use that instead?

[rpaquay, 2014/07/16 22:14:35]

hmmkay, that can be done. Where do you suggest I move the "UninstallReason" enum
definition (I was trying to follow the same pattern as UnloadedExtensionInfo)?

* If I leave in ExtensionService, it creates a strong dependency with
ExtensionRegistry
* If I create UninstalledExtensionInfo similar to UnloadeExtensionInfo, that new
type is not used anywhere (I am assuming
ExtensionRegistryObserver::OnExtensionUninstalled will follow the same pattern
as ExtensionRegistryObserver::OnExtensionUnloaded).

[Devlin, 2014/07/16 22:17:30]

I would actually say let's put it in its own file
(extensions/common/uninstall_reason.h).  It'll be used enough that it makes
sense, and that way people know where to look. ;)

[rpaquay, 2014/07/16 23:45:16]

Done.

   NOTIFICATION_EXTENSION_UNINSTALLED_DEPRECATED,
 
   // Sent when an extension uninstall is not allowed because the extension is