Remove usage of FOR_EACH_OBSERVER macro in components/signin

components/signin/core/browser/signin_manager.cc

Index: components/signin/core/browser/signin_manager.cc
diff --git a/components/signin/core/browser/signin_manager.cc b/components/signin/core/browser/signin_manager.cc
index cb537ec9e6d27a02d1ff34596b1b1012884ed1b3..3880fc1f6fb4b0efd40713527a77ab2563af189d 100644
--- a/components/signin/core/browser/signin_manager.cc
+++ b/components/signin/core/browser/signin_manager.cc
@@ -141,9 +141,8 @@ void SigninManager::ClearTransientSigninData() {
 void SigninManager::HandleAuthError(const GoogleServiceAuthError& error) {
   ClearTransientSigninData();
 
-  FOR_EACH_OBSERVER(SigninManagerBase::Observer,
-                    observer_list_,
-                    GoogleSigninFailed(error));
+  for (auto& observer : observer_list_)
+    observer.GoogleSigninFailed(error);
 }
 
 void SigninManager::SignOut(
@@ -201,9 +200,8 @@ void SigninManager::SignOut(
                << "IsSigninAllowed: " << IsSigninAllowed();
   token_service_->RevokeAllCredentials();
 
-  FOR_EACH_OBSERVER(SigninManagerBase::Observer,
-                    observer_list_,
-                    GoogleSignedOut(account_id, username));
+  for (auto& observer : observer_list_)
+    observer.GoogleSignedOut(account_id, username);
 }
 
 void SigninManager::Initialize(PrefService* local_state) {
@@ -375,10 +373,11 @@ void SigninManager::OnSignedIn() {
   possibly_invalid_email_.clear();
   signin_manager_signed_in_ = true;
 
-  FOR_EACH_OBSERVER(
-      SigninManagerBase::Observer, observer_list_,
-      GoogleSigninSucceeded(GetAuthenticatedAccountId(),
-                            GetAuthenticatedAccountInfo().email, password_));
+  for (auto& observer : observer_list_) {
+    observer.GoogleSigninSucceeded(GetAuthenticatedAccountId(),
+                                   GetAuthenticatedAccountInfo().email,
+                                   password_);
+  }
 
   client_->OnSignedIn(GetAuthenticatedAccountId(), gaia_id,
                       GetAuthenticatedAccountInfo().email, password_);