Reduce usage of FOR_EACH_OBSERVER macro in components/

components/prefs/testing_pref_store.cc

Index: components/prefs/testing_pref_store.cc
diff --git a/components/prefs/testing_pref_store.cc b/components/prefs/testing_pref_store.cc
index 2060c9fdcec25098eb06f112bfa87ffcccf8b414..1e775824a6a9ba1b7a3e6b7673f4b7ea24a7eaff 100644
--- a/components/prefs/testing_pref_store.cc
+++ b/components/prefs/testing_pref_store.cc
@@ -99,7 +99,8 @@ void TestingPrefStore::SetInitializationCompleted() {
 }
 
 void TestingPrefStore::NotifyPrefValueChanged(const std::string& key) {
-  FOR_EACH_OBSERVER(Observer, observers_, OnPrefValueChanged(key));
+  for (Observer& observer : observers_)
+    observer.OnPrefValueChanged(key);
 }
 
 void TestingPrefStore::NotifyInitializationCompleted() {
@@ -107,13 +108,14 @@ void TestingPrefStore::NotifyInitializationCompleted() {
   init_complete_ = true;
   if (read_success_ && read_error_ != PREF_READ_ERROR_NONE && error_delegate_)
     error_delegate_->OnError(read_error_);
-  FOR_EACH_OBSERVER(
-      Observer, observers_, OnInitializationCompleted(read_success_));
+  for (Observer& observer : observers_)
+    observer.OnInitializationCompleted(read_success_);
 }
 
 void TestingPrefStore::ReportValueChanged(const std::string& key,
                                           uint32_t flags) {
-  FOR_EACH_OBSERVER(Observer, observers_, OnPrefValueChanged(key));
+  for (Observer& observer : observers_)
+    observer.OnPrefValueChanged(key);
 }
 
 void TestingPrefStore::SetString(const std::string& key,