Fix user agent override restore pipeline

content/public/browser/notification_types.h

Index: content/public/browser/notification_types.h
diff --git a/content/public/browser/notification_types.h b/content/public/browser/notification_types.h
index a1122503301bea28ecd535a300a7ed0dc6252074..808038582a74835041c39b6dc31fdf29c43d382e 100644
--- a/content/public/browser/notification_types.h
+++ b/content/public/browser/notification_types.h
@@ -321,6 +321,10 @@ enum NotificationType {
   // the RenderViewHost, and the details is a DomOperationNotificationDetails.
   NOTIFICATION_DOM_OPERATION_RESPONSE,
 
+  // Notification from WebContents that its user agent override has been
+  // changed.
+  NOTIFICATION_WEB_CONTENTS_USER_AGENT_OVERRIDE_CHANGED,

[Charlie Reis, 2012/08/15 17:24:23]

John is typically against adding new notifications, but given that
SessionService appears to depend on them, this seems ok to me.

+
   // Child Processes ---------------------------------------------------------
 
   // This notification is sent when a child process host has connected to a