Allow DomDistillerService to have no store.

ios/chrome/browser/dom_distiller/dom_distiller_service_factory.cc

 // Copyright 2015 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 "ios/chrome/browser/dom_distiller/dom_distiller_service_factory.h"
 
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
@@ skipping 56 matching lines @@
     : BrowserStateKeyedServiceFactory(
           "DomDistillerService",
           BrowserStateDependencyManager::GetInstance()) {
 }
 
 DomDistillerServiceFactory::~DomDistillerServiceFactory() {}
 
 std::unique_ptr<KeyedService>
 DomDistillerServiceFactory::BuildServiceInstanceFor(
     web::BrowserState* context) const {
-  scoped_refptr<base::SequencedTaskRunner> background_task_runner =
-      web::WebThread::GetBlockingPool()->GetSequencedTaskRunner(
-          web::WebThread::GetBlockingPool()->GetSequenceToken());
-
-  std::unique_ptr<leveldb_proto::ProtoDatabaseImpl<ArticleEntry>> db =
-      base::MakeUnique<leveldb_proto::ProtoDatabaseImpl<ArticleEntry>>(
-          background_task_runner);
-
-  base::FilePath database_dir(
-      context->GetStatePath().Append(FILE_PATH_LITERAL("Articles")));
-
-  std::unique_ptr<DomDistillerStore> dom_distiller_store =
-      base::MakeUnique<DomDistillerStore>(std::move(db), database_dir);
 
   std::unique_ptr<DistillerPageFactory> distiller_page_factory =
       base::MakeUnique<DistillerPageFactoryIOS>(context);
 
   std::unique_ptr<DistillerURLFetcherFactory> distiller_url_fetcher_factory =
       base::MakeUnique<DistillerURLFetcherFactory>(
           context->GetRequestContext());
 
   dom_distiller::proto::DomDistillerOptions options;
   std::unique_ptr<DistillerFactory> distiller_factory =
       base::MakeUnique<DistillerFactoryImpl>(
           std::move(distiller_url_fetcher_factory), options);
   std::unique_ptr<DistilledPagePrefs> distilled_page_prefs =
       base::MakeUnique<DistilledPagePrefs>(
           ios::ChromeBrowserState::FromBrowserState(context)->GetPrefs());
 
   return base::MakeUnique<DomDistillerKeyedService>(
-      std::move(dom_distiller_store), std::move(distiller_factory),
-      std::move(distiller_page_factory), std::move(distilled_page_prefs));
+      nullptr, std::move(distiller_factory), std::move(distiller_page_factory),
+      std::move(distilled_page_prefs));
 }
 
 web::BrowserState* DomDistillerServiceFactory::GetBrowserStateToUse(
     web::BrowserState* context) const {
   // Makes normal profile and off-the-record profile use same service instance.
   return GetBrowserStateRedirectedInIncognito(context);
 }
 
 }  // namespace dom_distiller