Move enable extensions define to a build flag.

chrome/browser/policy/configuration_policy_handler_list_factory.cc

Index: chrome/browser/policy/configuration_policy_handler_list_factory.cc
diff --git a/chrome/browser/policy/configuration_policy_handler_list_factory.cc b/chrome/browser/policy/configuration_policy_handler_list_factory.cc
index b52e060e4ce2d09483301a1ed4935f4d320bb857..d81c768f5f0f4fd75a5d144edf0cb3ffefa2e581 100644
--- a/chrome/browser/policy/configuration_policy_handler_list_factory.cc
+++ b/chrome/browser/policy/configuration_policy_handler_list_factory.cc
@@ -49,6 +49,7 @@
 #include "components/sync/driver/sync_policy_handler.h"
 #include "components/translate/core/common/translate_pref_names.h"
 #include "components/variations/pref_names.h"
+#include "extensions/features/features.h"
 
 #if BUILDFLAG(ANDROID_JAVA_UI)
 #include "chrome/browser/search/contextual_search_policy_handler_android.h"
@@ -70,7 +71,7 @@
 #include "chrome/browser/download/download_dir_policy_handler.h"
 #endif
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/extensions/api/messaging/native_messaging_policy_handler.h"
 #include "chrome/browser/extensions/extension_management_constants.h"
 #include "chrome/browser/extensions/policy_handlers.h"
@@ -417,11 +418,11 @@ const PolicyToPreferenceMapEntry kSimplePolicyMap[] = {
   { key::kFullscreenAllowed,
     prefs::kFullscreenAllowed,
     base::Value::TYPE_BOOLEAN },
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   { key::kFullscreenAllowed,
     extensions::pref_names::kAppFullscreenAllowed,
     base::Value::TYPE_BOOLEAN },
-#endif  // defined(ENABLE_EXTENSIONS)
+#endif  // BUILDFLAG(ENABLE_EXTENSIONS)
 #endif  // !defined(OS_MACOSX)
 
 #if defined(OS_CHROMEOS)
@@ -689,7 +690,7 @@ class ForceYouTubeSafetyModePolicyHandler : public TypeCheckingPolicyHandler {
   DISALLOW_COPY_AND_ASSIGN(ForceYouTubeSafetyModePolicyHandler);
 };
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 void GetExtensionAllowedTypesMap(
     std::vector<std::unique_ptr<StringMappingListPolicyHandler::MappingEntry>>*
         result) {
@@ -771,7 +772,7 @@ std::unique_ptr<ConfigurationPolicyHandlerList> BuildHandlerList(
       prefs::kEnableDeprecatedWebPlatformFeatures,
       base::Bind(GetDeprecatedFeaturesMap)));
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   handlers->AddHandler(base::MakeUnique<extensions::ExtensionListPolicyHandler>(
       key::kExtensionInstallWhitelist,
       extensions::pref_names::kInstallAllowList, false));