Adds async interface method to PersistentPrefStore.

chrome/browser/prefs/testing_pref_store.cc

Index: chrome/browser/prefs/testing_pref_store.cc
diff --git a/chrome/browser/prefs/testing_pref_store.cc b/chrome/browser/prefs/testing_pref_store.cc
index e85a8368364e8f255be2cb070297676c37cc5314..869b8873e69257478505f1315769c7e1348dea8e 100644
--- a/chrome/browser/prefs/testing_pref_store.cc
+++ b/chrome/browser/prefs/testing_pref_store.cc
@@ -55,9 +55,20 @@ bool TestingPrefStore::ReadOnly() const {
 
 PersistentPrefStore::PrefReadError TestingPrefStore::ReadPrefs() {
   prefs_.Clear();
+  NotifyInitializationCompleted();
   return PersistentPrefStore::PREF_READ_ERROR_NONE;
 }
 
+void TestingPrefStore::ReadPrefsAsync() {
+  prefs_.Clear();
+  NotifyInitializationCompleted();
+}
+
+void TestingPrefStore::GetErrors(PrefReadError* error, bool* is_fatal) {
+  (*error) = PersistentPrefStore::PREF_READ_ERROR_NONE;
+  (*is_fatal) = false;
+}
+
 bool TestingPrefStore::WritePrefs() {
   prefs_written_ = true;
   return prefs_written_;