Convert Pass()→std::move() for iOS build.

ios/chrome/browser/bookmarks/bookmark_client_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/bookmarks/bookmark_client_factory.h"
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/keyed_service/ios/browser_state_dependency_manager.h"
 #include "ios/chrome/browser/bookmarks/bookmark_client_impl.h"
@@ skipping 31 matching lines @@
 BookmarkClientFactory::BookmarkClientFactory()
     : BrowserStateKeyedServiceFactory(
           "BookmarkClient",
           BrowserStateDependencyManager::GetInstance()) {
 }
 
 BookmarkClientFactory::~BookmarkClientFactory() {}
 
 scoped_ptr<KeyedService> BookmarkClientFactory::BuildServiceInstanceFor(
     web::BrowserState* context) const {
-  return BuildBookmarkClientImpl(context).Pass();
+  return BuildBookmarkClientImpl(context);
 }
 
 web::BrowserState* BookmarkClientFactory::GetBrowserStateToUse(
     web::BrowserState* context) const {
   return GetBrowserStateRedirectedInIncognito(context);
 }
 
 bool BookmarkClientFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }