Move enable_wifi_display out of root build configuration.

extensions/renderer/api/display_source/display_source_session.cc

Index: extensions/renderer/api/display_source/display_source_session.cc
diff --git a/extensions/renderer/api/display_source/display_source_session.cc b/extensions/renderer/api/display_source/display_source_session.cc
index ae2b67548386f4513efebe78de42a8c542954d51..99b60bb98b51fbd5b516de077afa73acb6bce713 100644
--- a/extensions/renderer/api/display_source/display_source_session.cc
+++ b/extensions/renderer/api/display_source/display_source_session.cc
@@ -4,7 +4,9 @@
 
 #include "extensions/renderer/api/display_source/display_source_session.h"
 
-#if defined(ENABLE_WIFI_DISPLAY)
+#include "extensions/features/features.h"
+
+#if BUILDFLAG(ENABLE_WIFI_DISPLAY)
 #include "extensions/renderer/api/display_source/wifi_display/wifi_display_session.h"
 #endif
 
@@ -38,7 +40,7 @@ void DisplaySourceSession::SetNotificationCallbacks(
 std::unique_ptr<DisplaySourceSession>
 DisplaySourceSessionFactory::CreateSession(
     const DisplaySourceSessionParams& params) {
-#if defined(ENABLE_WIFI_DISPLAY)
+#if BUILDFLAG(ENABLE_WIFI_DISPLAY)
   return std::unique_ptr<DisplaySourceSession>(new WiFiDisplaySession(params));
 #else
   return nullptr;