Extract LazyBackgroundTaskQueue from ExtensionSystem.

extensions/browser/api/runtime/runtime_api.cc

 // Copyright 2014 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/api/runtime/runtime_api.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 77 matching lines @@
     return;
 
   // If this is a persistent background page, we want to wait for it to load
   // (it might not be ready, since this is startup). But only enqueue once.
   // If it fails to load the first time, don't bother trying again.
   const Extension* extension =
       ExtensionRegistry::Get(browser_context)->enabled_extensions().GetByID(
           extension_id);
   if (extension && BackgroundInfo::HasPersistentBackgroundPage(extension) &&
       first_call &&
-      system->lazy_background_task_queue()->ShouldEnqueueTask(browser_context,
-                                                              extension)) {
-    system->lazy_background_task_queue()->AddPendingTask(
+      LazyBackgroundTaskQueue::Get(browser_context)->ShouldEnqueueTask(
+          browser_context, extension)) {
+    LazyBackgroundTaskQueue::Get(browser_context)->AddPendingTask(
         browser_context,
         extension_id,
         base::Bind(
             &DispatchOnStartupEventImpl, browser_context, extension_id, false));
     return;
   }
 
   scoped_ptr<base::ListValue> event_args(new base::ListValue());
   scoped_ptr<Event> event(
       new Event(runtime::OnStartup::kEventName, event_args.Pass()));
@@ skipping 286 matching lines @@
   GURL uninstall_url(
       GetUninstallURL(ExtensionPrefs::Get(context), extension_id));
 
   if (uninstall_url.is_empty())
     return;
 
   RuntimeAPI::GetFactoryInstance()->Get(context)->OpenURL(uninstall_url);
 }
 
 ExtensionFunction::ResponseAction RuntimeGetBackgroundPageFunction::Run() {
-  ExtensionSystem* system = ExtensionSystem::Get(browser_context());
   ExtensionHost* host = ProcessManager::Get(browser_context())
                             ->GetBackgroundHostForExtension(extension_id());
-  if (system->lazy_background_task_queue()->ShouldEnqueueTask(browser_context(),
-                                                              extension())) {
-    system->lazy_background_task_queue()->AddPendingTask(
+  if (LazyBackgroundTaskQueue::Get(browser_context())->ShouldEnqueueTask(
+          browser_context(), extension())) {
+    LazyBackgroundTaskQueue::Get(browser_context())->AddPendingTask(
         browser_context(),
         extension_id(),
         base::Bind(&RuntimeGetBackgroundPageFunction::OnPageLoaded, this));
   } else if (host) {
     OnPageLoaded(host);
   } else {
     return RespondNow(Error(kNoBackgroundPageError));
   }
 
   return RespondLater();
@@ skipping 95 matching lines @@
   content::ChildProcessSecurityPolicy* policy =
       content::ChildProcessSecurityPolicy::GetInstance();
   policy->GrantReadFileSystem(renderer_id, filesystem_id);
   base::DictionaryValue* dict = new base::DictionaryValue();
   dict->SetString("fileSystemId", filesystem_id);
   dict->SetString("baseName", relative_path);
   return RespondNow(OneArgument(dict));
 }
 
 }  // namespace extensions