Extract LazyBackgroundTaskQueue from ExtensionSystem.

extensions/browser/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 "extensions/browser/event_router.h"
 
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
@@ skipping 620 matching lines @@
       extension, context);
 }
 
 bool EventRouter::MaybeLoadLazyBackgroundPageToDispatchEvent(
     BrowserContext* context,
     const Extension* extension,
     const linked_ptr<Event>& event) {
   if (!CanDispatchEventToBrowserContext(context, extension, event))
     return false;
 
-  LazyBackgroundTaskQueue* queue = ExtensionSystem::Get(
-      context)->lazy_background_task_queue();
+  LazyBackgroundTaskQueue* queue = LazyBackgroundTaskQueue::Get(context);
   if (queue->ShouldEnqueueTask(context, extension)) {
     linked_ptr<Event> dispatched_event(event);
 
     // If there's a dispatch callback, call it now (rather than dispatch time)
     // to avoid lifetime issues. Use a separate copy of the event args, so they
     // last until the event is dispatched.
     if (!event->will_dispatch_callback.is_null()) {
       dispatched_event.reset(event->DeepCopy());
       if (!dispatched_event->will_dispatch_callback.Run(
               context, extension, dispatched_event->event_args.get())) {
@@ skipping 92 matching lines @@
       // Remove all event listeners associated with this renderer.
       listeners_.RemoveListenersForProcess(renderer);
       break;
     }
     case extensions::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 (BackgroundInfo::HasLazyBackgroundPage(extension)) {
-        LazyBackgroundTaskQueue* queue = ExtensionSystem::Get(
-            browser_context_)->lazy_background_task_queue();
+        LazyBackgroundTaskQueue* queue =
+            LazyBackgroundTaskQueue::Get(browser_context_);
         queue->AddPendingTask(browser_context_, extension->id(),
                               base::Bind(&DoNothing));
       }
       break;
     }
     default:
       NOTREACHED();
   }
 }
 
@@ skipping 66 matching lines @@
                                      const std::string& extension_id,
                                      const GURL& listener_url,
                                      content::BrowserContext* browser_context)
     : event_name(event_name),
       extension_id(extension_id),
       listener_url(listener_url),
       browser_context(browser_context) {
 }
 
 }  // namespace extensions