Convert RLZ to a buildflag header

chrome/browser/search_engines/ui_thread_search_terms_data.cc

Index: chrome/browser/search_engines/ui_thread_search_terms_data.cc
diff --git a/chrome/browser/search_engines/ui_thread_search_terms_data.cc b/chrome/browser/search_engines/ui_thread_search_terms_data.cc
index 6ae87fad55b2ab9e699aadcc0a9836624f302fc7..9a31685b52640c5fe56e2d0085624b76c859eb37 100644
--- a/chrome/browser/search_engines/ui_thread_search_terms_data.cc
+++ b/chrome/browser/search_engines/ui_thread_search_terms_data.cc
@@ -25,10 +25,11 @@
 #include "components/search/search.h"
 #include "components/version_info/version_info.h"
 #include "content/public/browser/browser_thread.h"
+#include "rlz/features/features.h"
 #include "ui/base/device_form_factor.h"
 #include "url/gurl.h"
 
-#if defined(ENABLE_RLZ)
+#if BUILDFLAG(ENABLE_RLZ)
 #include "components/rlz/rlz_tracker.h"
 #endif
 
@@ -74,7 +75,7 @@ base::string16 UIThreadSearchTermsData::GetRlzParameterValue(
   DCHECK(!BrowserThread::IsThreadInitialized(BrowserThread::UI) ||
       BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::string16 rlz_string;
-#if defined(ENABLE_RLZ)
+#if BUILDFLAG(ENABLE_RLZ)
   // For organic brandcodes do not use rlz at all. Empty brandcode usually
   // means a chromium install. This is ok.
   std::string brand;