Replace FOR_EACH_OBSERVER in components/drive with range-based for

components/drive/service/drive_api_service.cc

Index: components/drive/service/drive_api_service.cc
diff --git a/components/drive/service/drive_api_service.cc b/components/drive/service/drive_api_service.cc
index 59558fce4daab79f32c46de3bf515116686156c8..df82a503b06b80bcdacdfe453e7b94dbb157a83e 100644
--- a/components/drive/service/drive_api_service.cc
+++ b/components/drive/service/drive_api_service.cc
@@ -857,11 +857,11 @@ void DriveAPIService::ClearRefreshToken() {
 void DriveAPIService::OnOAuth2RefreshTokenChanged() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (CanSendRequest()) {
-    FOR_EACH_OBSERVER(
-        DriveServiceObserver, observers_, OnReadyToSendRequests());
+    for (auto& observer : observers_)
+      observer.OnReadyToSendRequests();
   } else if (!HasRefreshToken()) {
-    FOR_EACH_OBSERVER(
-        DriveServiceObserver, observers_, OnRefreshTokenInvalid());
+    for (auto& observer : observers_)
+      observer.OnRefreshTokenInvalid();
   }
 }