Replace FOR_EACH_OBSERVER in c/b/chromeos with range-based for

chrome/browser/chromeos/first_run/drive_first_run_controller.cc

Index: chrome/browser/chromeos/first_run/drive_first_run_controller.cc
diff --git a/chrome/browser/chromeos/first_run/drive_first_run_controller.cc b/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
index f5908cec4e78a632e035a51d7cc6f5b46ad55c85..a384608aaa01300d283a2741bf10d378900ce558 100644
--- a/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
+++ b/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
@@ -425,7 +425,8 @@ void DriveFirstRunController::SetAppInfoForTest(
 
 void DriveFirstRunController::OnWebContentsTimedOut() {
   LOG(WARNING) << "Timed out waiting for web contents.";
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnTimedOut());
+  for (auto& observer : observer_list_)
+    observer.OnTimedOut();
   OnOfflineInit(false, OUTCOME_WEB_CONTENTS_TIMED_OUT);
 }
 
@@ -442,7 +443,8 @@ void DriveFirstRunController::OnOfflineInit(bool success, UMAOutcome outcome) {
     ShowNotification();
   UMA_HISTOGRAM_ENUMERATION("DriveOffline.CrosAutoEnableOutcome",
                             outcome, OUTCOME_MAX);
-  FOR_EACH_OBSERVER(Observer, observer_list_, OnCompletion(success));
+  for (auto& observer : observer_list_)
+    observer.OnCompletion(success);
   CleanUp();
 }