Move enable extensions define to a build flag.

chrome/browser/download/chrome_download_manager_delegate.h

 // 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.
 
 #ifndef CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_
 #define CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/download/download_path_reservation_tracker.h"
 #include "chrome/browser/download/download_target_determiner_delegate.h"
 #include "chrome/browser/download/download_target_info.h"
 #include "chrome/browser/safe_browsing/download_protection_service.h"
 #include "content/public/browser/download_danger_type.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager_delegate.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "extensions/features/features.h"
 
 class DownloadPrefs;
 class Profile;
 
 namespace content {
 class DownloadManager;
 }
 
 namespace extensions {
 class CrxInstaller;
@@ skipping 123 matching lines @@
       std::unique_ptr<DownloadTargetInfo> target_info);
 
   // Returns true if |path| should open in the browser.
   bool IsOpenInBrowserPreferreredForFile(const base::FilePath& path);
 
   Profile* profile_;
   uint32_t next_download_id_;
   IdCallbackVector id_callbacks_;
   std::unique_ptr<DownloadPrefs> download_prefs_;
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   // Maps from pending extension installations to DownloadItem IDs.
   typedef base::hash_map<extensions::CrxInstaller*,
       content::DownloadOpenDelayedCallback> CrxInstallerMap;
   CrxInstallerMap crx_installers_;
 #endif
 
   content::NotificationRegistrar registrar_;
 
   base::WeakPtrFactory<ChromeDownloadManagerDelegate> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeDownloadManagerDelegate);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_CHROME_DOWNLOAD_MANAGER_DELEGATE_H_