Convert Sync BirthdayErrorTest to use FakeServer

chrome/browser/sync/test/integration/sync_test.h

Index: chrome/browser/sync/test/integration/sync_test.h
diff --git a/chrome/browser/sync/test/integration/sync_test.h b/chrome/browser/sync/test/integration/sync_test.h
index 6c32d8372a8f611a3cffd55905ee3d4db96b736f..c691a37fc9467c3caa424787e05f46de47926934 100644
--- a/chrome/browser/sync/test/integration/sync_test.h
+++ b/chrome/browser/sync/test/integration/sync_test.h
@@ -234,10 +234,6 @@ class SyncTest : public InProcessBrowserTest {
   // only if ServerSupportsErrorTriggering() returned true.
   void TriggerMigrationDoneError(syncer::ModelTypeSet model_types);
 
-  // Triggers the server to set its birthday to a random value thereby
-  // the server would return a birthday error on next sync.
-  void TriggerBirthdayError();
-
   // Triggers a transient error on the server. Note the server will stay in
   // this state until shut down.
   void TriggerTransientError();