Add a dummy export statement to files imported as ES modules.

Inside Google, we are making it a requirement for files that are imported using ES syntax to be "marked" with an import or export statement.

Change-Id: I2c137f228bdd5aa72c8f6b3f8bf1c7a9d5579eb1

gr-checks/gr-repo-chip.js

diff --git a/gr-checks/gr-repo-chip.js b/gr-checks/gr-repo-chip.js
index 2f20dfe..4454ebc 100644
--- a/gr-checks/gr-repo-chip.js
+++ b/gr-checks/gr-repo-chip.js
@@ -78,4 +78,6 @@
   }
 }
 
-customElements.define(GrRepoChip.is, GrRepoChip);
\ No newline at end of file
+customElements.define(GrRepoChip.is, GrRepoChip);
+
+export {};