TBR: Fix copyright issue in generated mojom.dart file.

Change-Id: Ibc43db7d34ef7a940ce7f69ff004386a2fac2f9d
diff --git a/.jiriignore b/.jiriignore
new file mode 100644
index 0000000..635d5e1
--- /dev/null
+++ b/.jiriignore
@@ -0,0 +1 @@
+dart/lib/gen/dart-gen/mojom/lib/mojo/syncbase.mojom.dart