Reduce usage of FOR_EACH_OBSERVER macro in chrome/browser

chrome/browser/engagement/site_engagement_service.cc

Index: chrome/browser/engagement/site_engagement_service.cc
diff --git a/chrome/browser/engagement/site_engagement_service.cc b/chrome/browser/engagement/site_engagement_service.cc
index 4437b54d108e40c9691a0789fe3473d65a794641..ea4f28470e2edb3876db1b9d0a6528a6b11ac16b 100644
--- a/chrome/browser/engagement/site_engagement_service.cc
+++ b/chrome/browser/engagement/site_engagement_service.cc
@@ -434,9 +434,8 @@ void SiteEngagementService::HandleMediaPlaying(
                            : SiteEngagementScore::GetVisibleMediaPoints());
 
   RecordMetrics();
-  FOR_EACH_OBSERVER(
-      SiteEngagementObserver, observer_list_,
-      OnEngagementIncreased(web_contents, url, GetScore(url)));
+  for (SiteEngagementObserver& observer : observer_list_)
+    observer.OnEngagementIncreased(web_contents, url, GetScore(url));
 }
 
 void SiteEngagementService::HandleNavigation(content::WebContents* web_contents,
@@ -448,9 +447,8 @@ void SiteEngagementService::HandleNavigation(content::WebContents* web_contents,
     AddPoints(url, SiteEngagementScore::GetNavigationPoints());
 
     RecordMetrics();
-    FOR_EACH_OBSERVER(
-        SiteEngagementObserver, observer_list_,
-        OnEngagementIncreased(web_contents, url, GetScore(url)));
+    for (SiteEngagementObserver& observer : observer_list_)
+      observer.OnEngagementIncreased(web_contents, url, GetScore(url));
   }
 }
 
@@ -462,9 +460,8 @@ void SiteEngagementService::HandleUserInput(
   AddPoints(url, SiteEngagementScore::GetUserInputPoints());
 
   RecordMetrics();
-  FOR_EACH_OBSERVER(
-      SiteEngagementObserver, observer_list_,
-      OnEngagementIncreased(web_contents, url, GetScore(url)));
+  for (SiteEngagementObserver& observer : observer_list_)
+    observer.OnEngagementIncreased(web_contents, url, GetScore(url));
 }
 
 bool SiteEngagementService::IsLastEngagementStale() const {