Remove usage of FOR_EACH_OBSERVER macro in net

net/url_request/url_request_context_getter.cc

Index: net/url_request/url_request_context_getter.cc
diff --git a/net/url_request/url_request_context_getter.cc b/net/url_request/url_request_context_getter.cc
index 022aa0f958c3c9f7fe520101996c0d8194915444..0bad74812804739ecd53fae8180316ed33213818 100644
--- a/net/url_request/url_request_context_getter.cc
+++ b/net/url_request/url_request_context_getter.cc
@@ -57,8 +57,8 @@ void URLRequestContextGetter::NotifyContextShuttingDown() {
   // Once shutdown starts, this must always return NULL.
   DCHECK(!GetURLRequestContext());
 
-  FOR_EACH_OBSERVER(URLRequestContextGetterObserver, observer_list_,
-                    OnContextShuttingDown());
+  for (auto& observer : observer_list_)
+    observer.OnContextShuttingDown();
 }
 
 TrivialURLRequestContextGetter::TrivialURLRequestContextGetter(