Move session service and supervised users to buildflags.

chrome/browser/search/search.cc

Index: chrome/browser/search/search.cc
diff --git a/chrome/browser/search/search.cc b/chrome/browser/search/search.cc
index 79c0c2396d9719894753b68b3dd90e7f4b1f2673..1d975cce78760a70b072c26450e4a829d9f1c523 100644
--- a/chrome/browser/search/search.cc
+++ b/chrome/browser/search/search.cc
@@ -24,6 +24,7 @@
 #include "chrome/browser/ui/browser_instant_controller.h"
 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/features.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/search/search_urls.h"
 #include "chrome/common/url_constants.h"
@@ -38,7 +39,7 @@
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/web_contents.h"
 
-#if defined(ENABLE_SUPERVISED_USERS)
+#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
 #include "chrome/browser/supervised_user/supervised_user_service.h"
 #include "chrome/browser/supervised_user/supervised_user_service_factory.h"
 #include "chrome/browser/supervised_user/supervised_user_url_filter.h"
@@ -149,7 +150,7 @@ bool IsInstantURL(const GURL& url, Profile* profile) {
 }
 
 bool IsURLAllowedForSupervisedUser(const GURL& url, Profile* profile) {
-#if defined(ENABLE_SUPERVISED_USERS)
+#if BUILDFLAG(ENABLE_SUPERVISED_USERS)
   SupervisedUserService* supervised_user_service =
       SupervisedUserServiceFactory::GetForProfile(profile);
   SupervisedUserURLFilter* url_filter =