Install deprecated JS API

This is required for self.onAction() to work

Change-Id: Ideb554f7b8f4b349ddcd55e5a08ef8ebe1ada900
diff --git a/src/main/resources/static/find-owners.js b/src/main/resources/static/find-owners.js
index 7ab6b80..0abdabe 100644
--- a/src/main/resources/static/find-owners.js
+++ b/src/main/resources/static/find-owners.js
@@ -13,6 +13,11 @@
 // limitations under the License.
 
 Gerrit.install(function(self) {
+  if (window.Polymer) {
+    // Install deprecated APIs to mimic GWT UI API.
+    self.deprecated.install();
+  }
+
   // If context.popup API exists and popup content is small,
   // use the API and set useContextPopup,
   // otherwise, use pageDiv and set its visibility.