[Sync] Sanity test for UserEvents.

chrome/browser/sync/test/integration/migration_test.cc

Index: chrome/browser/sync/test/integration/migration_test.cc
diff --git a/chrome/browser/sync/test/integration/migration_test.cc b/chrome/browser/sync/test/integration/migration_test.cc
index 848b93b6853c1cd32e5e6ba04d5432e2f0cf37b2..582d374e3afccde20ba86e2a154e8a4eb5a48d4a 100644
--- a/chrome/browser/sync/test/integration/migration_test.cc
+++ b/chrome/browser/sync/test/integration/migration_test.cc
@@ -112,6 +112,9 @@ class MigrationTest : public SyncTest  {
     // that it be migrated.
     preferred_data_types.Remove(syncer::ARC_PACKAGE);
 
+    // Doesn't make sense to migrate commit only types.
+    preferred_data_types.RemoveAll(syncer::CommitOnlyTypes());
+
     // Make sure all clients have the same preferred data types.
     for (int i = 1; i < num_clients(); ++i) {
       const syncer::ModelTypeSet other_preferred_data_types =
@@ -162,6 +165,7 @@ class MigrationTest : public SyncTest  {
   // types.
   void AwaitMigration(syncer::ModelTypeSet migrate_types) {
     for (int i = 0; i < num_clients(); ++i) {
+      LOG(ERROR) << "SKYM " << syncer::ModelTypeSetToString(migrate_types);

[Patrick Noland, 2017/06/26 19:20:23]

Did you mean to include this? If so, could you make the message a bit for
informative?

[skym, 2017/06/26 19:59:40]

I did not! Whoops. Removed.

       ASSERT_TRUE(
           MigrationWaiter(migrate_types, migration_watchers_[i].get()).Wait());
     }