Close popup window when leaving a page

Change-Id: I70cc9033edd971fc4fefd1416448c22814f91478

src/main/resources/static/find-owners.js

diff --git a/src/main/resources/static/find-owners.js b/src/main/resources/static/find-owners.js
index c773aa9..db4ca99 100644
--- a/src/main/resources/static/find-owners.js
+++ b/src/main/resources/static/find-owners.js
@@ -597,4 +597,6 @@
   self.on('submitchange', onSubmit);
   // Clicks outside the pop up window should close the window.
   document.body.addEventListener('click', onClick);
+  // Leaving page should close the window.
+  window.addEventListener('popstate', hideFindOwnersPage);
 });