Add the ability to schedule any pending lossy prefs to be written.

base/prefs/testing_pref_store.cc

Index: base/prefs/testing_pref_store.cc
diff --git a/base/prefs/testing_pref_store.cc b/base/prefs/testing_pref_store.cc
index 35c9763eec5b15c3a27ef375750dd45adbd6a3e3..1a1e6bcd0f5b120c43f6cd1c9b5c418bd7e1e030 100644
--- a/base/prefs/testing_pref_store.cc
+++ b/base/prefs/testing_pref_store.cc
@@ -89,6 +89,8 @@ void TestingPrefStore::ReadPrefsAsync(ReadErrorDelegate* error_delegate) {
 
 void TestingPrefStore::CommitPendingWrite() { committed_ = true; }
 
+void TestingPrefStore::SchedulePendingLossyWrites() {}
+
 void TestingPrefStore::SetInitializationCompleted() {
   NotifyInitializationCompleted();
 }