Move enable extensions define to a build flag.

chrome/browser/plugins/plugin_info_message_filter.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_PLUGINS_PLUGIN_INFO_MESSAGE_FILTER_H_
 #define CHROME_BROWSER_PLUGINS_PLUGIN_INFO_MESSAGE_FILTER_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "chrome/browser/plugins/plugin_prefs.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/prefs/pref_member.h"
 #include "content/public/browser/browser_message_filter.h"
+#include "extensions/features/features.h"
 #include "ppapi/features/features.h"
 
 struct ChromeViewHostMsg_GetPluginInfo_Output;
 enum class ChromeViewHostMsg_GetPluginInfo_Status;
 class GURL;
 class HostContentSettingsMap;
 class PluginFinder;
 class PluginMetadata;
 class Profile;
 
@@ skipping 44 matching lines @@
         content::WebPluginInfo* plugin,
         std::string* actual_mime_type,
         std::unique_ptr<PluginMetadata>* plugin_metadata) const;
     void MaybeGrantAccess(ChromeViewHostMsg_GetPluginInfo_Status status,
                           const base::FilePath& path) const;
     bool IsPluginEnabled(const content::WebPluginInfo& plugin) const;
 
    private:
     int render_process_id_;
     content::ResourceContext* resource_context_;
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
     extensions::ExtensionRegistry* extension_registry_;
 #endif
     const HostContentSettingsMap* host_content_settings_map_;
     scoped_refptr<PluginPrefs> plugin_prefs_;
 
     BooleanPrefMember allow_outdated_plugins_;
     BooleanPrefMember always_authorize_plugins_;
   };
 
   PluginInfoMessageFilter(int render_process_id, Profile* profile);
@@ skipping 51 matching lines @@
 
   Context context_;
 
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
   base::WeakPtrFactory<PluginInfoMessageFilter> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginInfoMessageFilter);
 };
 
 #endif  // CHROME_BROWSER_PLUGINS_PLUGIN_INFO_MESSAGE_FILTER_H_