Force-load a lazy background page whenever an extension is enabled.

chrome/browser/extensions/event_router.cc

Index: chrome/browser/extensions/event_router.cc
diff --git a/chrome/browser/extensions/event_router.cc b/chrome/browser/extensions/event_router.cc
index 213299b2f6c879663028f330231dd5427f0243b5..3fe9f1622a16e76c62c8d9335795ef4f45a590d4 100644
--- a/chrome/browser/extensions/event_router.cc
+++ b/chrome/browser/extensions/event_router.cc
@@ -65,6 +65,8 @@ void DispatchOnInstalledEvent(
                                                old_version, chrome_updated);
 }
 
+void DoNothing(extensions::ExtensionHost* host) {}
+
 }  // namespace
 
 struct EventRouter::ListenerProcess {
@@ -128,6 +130,8 @@ EventRouter::EventRouter(Profile* profile, ExtensionPrefs* extension_prefs)
                  content::NotificationService::AllSources());
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
                  content::Source<Profile>(profile_));
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_ENABLED,
+                 content::Source<Profile>(profile_));
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
                  content::Source<Profile>(profile_));
   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
@@ -606,6 +610,18 @@ void EventRouter::Observe(int type,
       dispatch_chrome_updated_event_ = false;
       break;
     }
+    case chrome::NOTIFICATION_EXTENSION_ENABLED: {
+      // If the extension has a lazy background page, make sure it gets loaded
+      // to register the events the extension is interested in.
+      const Extension* extension =
+          content::Details<const Extension>(details).ptr();
+      if (extension->has_lazy_background_page()) {
+        LazyBackgroundTaskQueue* queue =
+            ExtensionSystem::Get(profile_)->lazy_background_task_queue();
+        queue->AddPendingTask(profile_, extension->id(),
+                              base::Bind(&DoNothing));
+      }
+    }
     case chrome::NOTIFICATION_EXTENSION_LOADED: {
       // Add all registered lazy listeners to our cache.
       const Extension* extension =