Set up the infrastructure for Extension event metrics.

chrome/browser/extensions/api/developer_private/developer_private_api.cc

Index: chrome/browser/extensions/api/developer_private/developer_private_api.cc
diff --git a/chrome/browser/extensions/api/developer_private/developer_private_api.cc b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
index 2c1516aaf31928558e1954b06274c9cb34f0d68d..811a3636b8a597c820877157d731360386744675 100644
--- a/chrome/browser/extensions/api/developer_private/developer_private_api.cc
+++ b/chrome/browser/extensions/api/developer_private/developer_private_api.cc
@@ -341,8 +341,9 @@ void DeveloperPrivateEventRouter::OnExtensionDisableReasonsChanged(
 void DeveloperPrivateEventRouter::OnExtensionManagementSettingsChanged() {
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->Append(CreateProfileInfo(profile_)->ToValue());
-  scoped_ptr<Event> event(new Event(
-      developer::OnProfileStateChanged::kEventName, args.Pass()));
+  scoped_ptr<Event> event(
+      new Event(events::UNKNOWN, developer::OnProfileStateChanged::kEventName,
+                args.Pass()));
   event_router_->BroadcastEvent(event.Pass());
 }
 
@@ -391,7 +392,7 @@ void DeveloperPrivateEventRouter::BroadcastItemStateChangedHelper(
   scoped_ptr<base::ListValue> args(new base::ListValue());
   args->Append(dict.release());
   scoped_ptr<Event> event(new Event(
-      developer::OnItemStateChanged::kEventName, args.Pass()));
+      events::UNKNOWN, developer::OnItemStateChanged::kEventName, args.Pass()));
   event_router_->BroadcastEvent(event.Pass());
 }