Use tab.url (works if the page doesn't reflect the changed URL; also fixes an issue with Maps not getting navigation information)

extension/content_script.js

@@ -16,7 +16,6 @@
 
 var additionalInfo = {
   "title": document.title,
-  "url": document.location.href,
   "selection": window.getSelection().toString()
 };
 

extension/popup.html

@@ -77,7 +77,7 @@ chrome.extension.onConnect.addListener(function(port) {
     if (info.selection.length > max_length) {
       info.selection = info.selection.substring(0, max_length);
     }
-    sendToPhone(info.title, info.url, info.selection);
+    sendToPhone(info.title, tab.url, info.selection);
   });
 });