Reduce FOR_EACH_OBSERVER usage in extensions

extensions/renderer/user_script_set_manager.cc

Index: extensions/renderer/user_script_set_manager.cc
diff --git a/extensions/renderer/user_script_set_manager.cc b/extensions/renderer/user_script_set_manager.cc
index 3b630671c8cc3302bf332e3c2d097e9caa2fec41..8108c041d7825557602e41fe9c6e5d755c3cb679 100644
--- a/extensions/renderer/user_script_set_manager.cc
+++ b/extensions/renderer/user_script_set_manager.cc
@@ -151,8 +151,8 @@ void UserScriptSetManager::OnUpdateUserScripts(
   if (scripts->UpdateUserScripts(shared_memory,
                                  *effective_hosts,
                                  whitelisted_only)) {
-    FOR_EACH_OBSERVER(Observer, observers_,
-                      OnUserScriptsUpdated(*effective_hosts));
+    for (auto& observer : observers_)
+      observer.OnUserScriptsUpdated(*effective_hosts);
   }
 }