Reduce usage of FOR_EACH_OBSERVER macro in chrome/browser/signin

chrome/browser/signin/cross_device_promo.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/signin/cross_device_promo.h"
 
 #include <stdint.h>
 
 #include "base/metrics/histogram_macros.h"
 #include "base/rand_util.h"
@@ skipping 265 matching lines @@
   signin_metrics::LogXDevicePromoInitialized(signin_metrics::INITIALIZED);
   return;
 }
 
 void CrossDevicePromo::MarkPromoShouldBeShown() {
   VLOG(1) << "CrossDevicePromo::MarkPromoShouldBeShown.";
   DCHECK(!prefs_->GetBoolean(prefs::kCrossDevicePromoOptedOut));
 
   if (!prefs_->GetBoolean(prefs::kCrossDevicePromoShouldBeShown)) {
     prefs_->SetBoolean(prefs::kCrossDevicePromoShouldBeShown, true);
-    FOR_EACH_OBSERVER(CrossDevicePromo::Observer, observer_list_,
-                      OnPromoEligibilityChanged(true));
+    for (CrossDevicePromo::Observer& observer : observer_list_)
+      observer.OnPromoEligibilityChanged(true);
   }
 }
 
 void CrossDevicePromo::MarkPromoShouldNotBeShown() {
   VLOG(1) << "CrossDevicePromo::MarkPromoShouldNotBeShown.";
   if (prefs_->GetBoolean(prefs::kCrossDevicePromoShouldBeShown)) {
     prefs_->SetBoolean(prefs::kCrossDevicePromoShouldBeShown, false);
-    FOR_EACH_OBSERVER(CrossDevicePromo::Observer, observer_list_,
-                      OnPromoEligibilityChanged(false));
+    for (CrossDevicePromo::Observer& observer : observer_list_)
+      observer.OnPromoEligibilityChanged(false);
   }
 }
 
 bool CrossDevicePromo::CheckPromoEligibility() {
   if (!initialized_)
     return false;
 
   if (prefs_->GetBoolean(prefs::kCrossDevicePromoOptedOut)) {
     signin_metrics::LogXDevicePromoEligible(signin_metrics::OPTED_OUT);
     return false;
@@ skipping 143 matching lines @@
   device_activity_fetcher_->Start();
 }
 
 void CrossDevicePromo::RegisterForCookieChanges() {
   cookie_manager_service_->AddObserver(this);
 }
 
 void CrossDevicePromo::UnregisterForCookieChanges() {
   cookie_manager_service_->RemoveObserver(this);
 }