Added CHECKs for null pointers in ChromeAppSorting.

extensions/browser/null_app_sorting.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/null_app_sorting.h"
 
 #include "sync/api/string_ordinal.h"
 
 namespace {
 
 // Ordinals for a single app on a single page.
 const char kFirstApp[] = "a";
 const char kNextApp[] = "b";
 const char kFirstPage[] = "a";
 
 }  // namespace
 
 namespace extensions {
 
 NullAppSorting::NullAppSorting() {
 }
 
 NullAppSorting::~NullAppSorting() {
 }
 
 void NullAppSorting::SetExtensionScopedPrefs(ExtensionScopedPrefs* prefs) {
 }
 
+void NullAppSorting::CheckExtensionScopedPrefs() const {
+}
+
 void NullAppSorting::SetExtensionSyncService(
     ExtensionSyncService* extension_sync_service) {
 }
 
 void NullAppSorting::Initialize(const ExtensionIdList& extension_ids) {
 }
 
 void NullAppSorting::FixNTPOrdinalCollisions() {
 }
 
@@ skipping 57 matching lines @@
 syncer::StringOrdinal NullAppSorting::PageIntegerAsStringOrdinal(
     size_t page_index) {
   return syncer::StringOrdinal(kFirstPage);
 }
 
 void NullAppSorting::SetExtensionVisible(const std::string& extension_id,
                                          bool visible) {
 }
 
 }  // namespace extensions