[Sync] Convert syncable/ directory to ModelEnumSet

chrome/browser/sync/syncable/directory_change_delegate.h

Index: chrome/browser/sync/syncable/directory_change_delegate.h
diff --git a/chrome/browser/sync/syncable/directory_change_delegate.h b/chrome/browser/sync/syncable/directory_change_delegate.h
index 99b364fe60fc937576a6aa9770ab1cd88d44daab..3ccae2c64797b8d5dbdffacd9d1a74146a91a6f0 100644
--- a/chrome/browser/sync/syncable/directory_change_delegate.h
+++ b/chrome/browser/sync/syncable/directory_change_delegate.h
@@ -31,11 +31,11 @@ class DirectoryChangeDelegate {
       BaseTransaction* trans) = 0;
   // Must return the set of all ModelTypes that were modified in the
   // transaction.
-  virtual ModelTypeBitSet HandleTransactionEndingChangeEvent(
+  virtual ModelEnumSet HandleTransactionEndingChangeEvent(
       const ImmutableWriteTransactionInfo& write_transaction_info,
       BaseTransaction* trans) = 0;
   virtual void HandleTransactionCompleteChangeEvent(
-      const ModelTypeBitSet& models_with_changes) = 0;
+      ModelEnumSet models_with_changes) = 0;
  protected:
   virtual ~DirectoryChangeDelegate() {}
 };