Move enable extensions define to a build flag.

chrome/browser/prerender/prerender_manager_factory.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 "chrome/browser/prerender/prerender_manager_factory.h"
 
 #include "base/trace_event/trace_event.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/predictors/predictor_database_factory.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "extensions/features/features.h"
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/browser/extension_system_provider.h"
 #include "extensions/browser/extensions_browser_client.h"
 #endif
 
 namespace prerender {
 
 // static
 PrerenderManager* PrerenderManagerFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   TRACE_EVENT0("browser", "PrerenderManagerFactory::GetForProfile")
   if (!PrerenderManager::IsPrerenderingPossible())
     return NULL;
   return static_cast<PrerenderManager*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 PrerenderManagerFactory* PrerenderManagerFactory::GetInstance() {
   return base::Singleton<PrerenderManagerFactory>::get();
 }
 
 PrerenderManagerFactory::PrerenderManagerFactory()
     : BrowserContextKeyedServiceFactory(
         "PrerenderManager",
         BrowserContextDependencyManager::GetInstance()) {
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   DependsOn(
       extensions::ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
 #endif
   // PrerenderLocalPredictor observers the history visit DB.
   DependsOn(HistoryServiceFactory::GetInstance());
   DependsOn(predictors::PredictorDatabaseFactory::GetInstance());
   DependsOn(ProfileSyncServiceFactory::GetInstance());
 }
 
 PrerenderManagerFactory::~PrerenderManagerFactory() {
 }
 
 KeyedService* PrerenderManagerFactory::BuildServiceInstanceFor(
     content::BrowserContext* browser_context) const {
   return new PrerenderManager(Profile::FromBrowserContext(browser_context));
 }
 
 content::BrowserContext* PrerenderManagerFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return chrome::GetBrowserContextOwnInstanceInIncognito(context);
 }
 
 }  // namespace prerender