Move enable extensions define to a build flag.

chrome/browser/prefs/chrome_pref_service_factory.cc

Index: chrome/browser/prefs/chrome_pref_service_factory.cc
diff --git a/chrome/browser/prefs/chrome_pref_service_factory.cc b/chrome/browser/prefs/chrome_pref_service_factory.cc
index fe58fc30c7a23bad5cd0d18484b1795fe25f9752..0c761e6d9efbe545b39e813f7863a1adb353abfa 100644
--- a/chrome/browser/prefs/chrome_pref_service_factory.cc
+++ b/chrome/browser/prefs/chrome_pref_service_factory.cc
@@ -58,10 +58,11 @@
 #include "components/user_prefs/tracked/pref_names.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
+#include "extensions/features/features.h"
 #include "sql/error_delegate_util.h"
 #include "ui/base/resource/resource_bundle.h"
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/browser/pref_names.h"
 #endif
 
@@ -125,7 +126,7 @@ const PrefHashFilter::TrackedPreferenceMetadata kTrackedPrefs[] = {
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC,
     PrefHashFilter::VALUE_IMPERSONAL
   },
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
   {
     5, extensions::pref_names::kExtensions,
     PrefHashFilter::NO_ENFORCEMENT,
@@ -341,7 +342,7 @@ GetTrackingConfiguration() {
       data.enforcement_level = PrefHashFilter::ENFORCE_ON_LOAD;
     }
 
-#if defined(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_EXTENSIONS)
     if (enforcement_group >= GROUP_ENFORCE_ALWAYS_WITH_EXTENSIONS_AND_DSE &&
         data.name == extensions::pref_names::kExtensions) {
       // Specifically enable extension settings enforcement.