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

chrome/browser/chromeos/options/cert_library.cc

Index: chrome/browser/chromeos/options/cert_library.cc
diff --git a/chrome/browser/chromeos/options/cert_library.cc b/chrome/browser/chromeos/options/cert_library.cc
index 241debb4a3a9b458c68252626449f0e257bbaf10..00084f64e07166fe44c48033642dcd9084df14c0 100644
--- a/chrome/browser/chromeos/options/cert_library.cc
+++ b/chrome/browser/chromeos/options/cert_library.cc
@@ -250,8 +250,8 @@ void CertLibrary::OnCertificatesLoaded(const net::CertificateList& cert_list,
   VLOG(1) << "server_certs_: " << server_certs_.size();
   VLOG(1) << "server_ca_certs_: " << server_ca_certs_.size();
 
-  FOR_EACH_OBSERVER(CertLibrary::Observer, observer_list_,
-                    OnCertificatesLoaded(initial_load));
+  for (auto& observer : observer_list_)
+    observer.OnCertificatesLoaded(initial_load);
 }
 
 net::X509Certificate* CertLibrary::GetCertificateAt(CertType type,