Move enable extensions define to a build flag.

chrome/browser/sync/chrome_sync_client.cc

Index: chrome/browser/sync/chrome_sync_client.cc
diff --git a/chrome/browser/sync/chrome_sync_client.cc b/chrome/browser/sync/chrome_sync_client.cc
index 2aa52e98db278d8e3dc9bde8f6a0035d5e04c1ca..7551d440fb880e6b2d959b5e04333dc2ca5b0d6d 100644
--- a/chrome/browser/sync/chrome_sync_client.cc
+++ b/chrome/browser/sync/chrome_sync_client.cc
@@ -64,6 +64,7 @@
 #include "components/sync_preferences/pref_service_syncable.h"
 #include "components/sync_sessions/sync_sessions_client.h"
 #include "content/public/browser/browser_thread.h"
+#include "extensions/features/features.h"
 #include "ui/base/device_form_factor.h"
 
 #if BUILDFLAG(ENABLE_APP_LIST)
@@ -72,7 +73,7 @@
 #include "ui/app_list/app_list_switches.h"
 #endif
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/extensions/api/storage/settings_sync_util.h"
 #include "chrome/browser/extensions/extension_sync_service.h"
 #include "chrome/browser/sync/glue/extension_data_type_controller.h"
@@ -109,7 +110,7 @@
 #endif
 
 using content::BrowserThread;
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 using browser_sync::ExtensionDataTypeController;
 using browser_sync::ExtensionSettingDataTypeController;
 #endif
@@ -329,7 +330,7 @@ ChromeSyncClient::GetSyncableServiceForType(syncer::ModelType type) {
     }
     case syncer::SEARCH_ENGINES:
       return TemplateURLServiceFactory::GetForProfile(profile_)->AsWeakPtr();
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
     case syncer::APPS:
     case syncer::EXTENSIONS:
       return ExtensionSyncService::Get(profile_)->AsWeakPtr();
@@ -514,7 +515,7 @@ void ChromeSyncClient::RegisterDesktopDataTypes(
   base::Closure error_callback =
       base::Bind(&syncer::ReportUnrecoverableError, chrome::GetChannel());
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   // App sync is enabled by default.  Register unless explicitly
   // disabled.
   if (!disabled_types.Has(syncer::APPS)) {
@@ -550,7 +551,7 @@ void ChromeSyncClient::RegisterDesktopDataTypes(
             TemplateURLServiceFactory::GetForProfile(profile_)));
   }
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   // Extension setting sync is enabled by default.  Register unless explicitly
   // disabled.
   if (!disabled_types.Has(syncer::EXTENSION_SETTINGS)) {