[Sync] Make GetFirstChildId return a flag indicating success

chrome/browser/sync/engine/nigori_util.h

Index: chrome/browser/sync/engine/nigori_util.h
diff --git a/chrome/browser/sync/engine/nigori_util.h b/chrome/browser/sync/engine/nigori_util.h
index d3d25ddc0abd5e9d5f3379114d9b2ac0584e62a1..5ffc8995e323d13bb63515d615683ddf247972c1 100644
--- a/chrome/browser/sync/engine/nigori_util.h
+++ b/chrome/browser/sync/engine/nigori_util.h
@@ -55,10 +55,11 @@ bool SpecificsNeedsEncryption(const ModelTypeSet& encrypted_types,
                               const sync_pb::EntitySpecifics& specifics);
 
 // Verifies all data of type |type| is encrypted appropriately.
-bool VerifyDataTypeEncryption(BaseTransaction* const trans,
-                              browser_sync::Cryptographer* cryptographer,
-                              ModelType type,
-                              bool is_encrypted);
+bool VerifyDataTypeEncryptionForTest(
+    BaseTransaction* const trans,
+    browser_sync::Cryptographer* cryptographer,
+    ModelType type,
+    bool is_encrypted);
 
 }  // namespace syncable