Remove usage of FOR_EACH_OBSERVER macro in google_apis

google_apis/gaia/account_tracker.cc

Index: google_apis/gaia/account_tracker.cc
diff --git a/google_apis/gaia/account_tracker.cc b/google_apis/gaia/account_tracker.cc
index 0a2cce054d3178aec1fe71276bb1bac18804af57..c00e5bdc681b82d0f6682fbeefe0fc9d6aa72c5f 100644
--- a/google_apis/gaia/account_tracker.cc
+++ b/google_apis/gaia/account_tracker.cc
@@ -154,14 +154,14 @@ void AccountTracker::SetAccountStateForTest(AccountIds ids, bool is_signed_in) {
 
 void AccountTracker::NotifyAccountAdded(const AccountState& account) {
   DCHECK(!account.ids.gaia.empty());
-  FOR_EACH_OBSERVER(
-      Observer, observer_list_, OnAccountAdded(account.ids));
+  for (auto& observer : observer_list_)
+    observer.OnAccountAdded(account.ids);
 }
 
 void AccountTracker::NotifyAccountRemoved(const AccountState& account) {
   DCHECK(!account.ids.gaia.empty());
-  FOR_EACH_OBSERVER(
-      Observer, observer_list_, OnAccountRemoved(account.ids));
+  for (auto& observer : observer_list_)
+    observer.OnAccountRemoved(account.ids);
 }
 
 void AccountTracker::NotifySignInChanged(const AccountState& account) {
@@ -172,9 +172,8 @@ void AccountTracker::NotifySignInChanged(const AccountState& account) {
           "422460 AccountTracker::NotifySignInChanged"));
 
   DCHECK(!account.ids.gaia.empty());
-  FOR_EACH_OBSERVER(Observer,
-                    observer_list_,
-                    OnAccountSignInChanged(account.ids, account.is_signed_in));
+  for (auto& observer : observer_list_)
+    observer.OnAccountSignInChanged(account.ids, account.is_signed_in);
 }
 
 void AccountTracker::UpdateSignInState(const std::string& account_key,