Set the attach file checkbox to checked when launched from an extension.

chrome/browser/resources/feedback.js

Index: chrome/browser/resources/feedback.js
diff --git a/chrome/browser/resources/feedback.js b/chrome/browser/resources/feedback.js
index 14ae6fb950a2fda2eb8746aa7bf79f169de75f93..15d37ec97a13eee541fdc77ebfd7d43458df80d9 100644
--- a/chrome/browser/resources/feedback.js
+++ b/chrome/browser/resources/feedback.js
@@ -305,7 +305,14 @@ function load() {
     'filePath': '',
   };
 
-  var query = window.location.search.substr(1).split('&');
+  var loc = window.location;
+  // Split the query string into an array of parameters.
+  var query = loc.search.substr(1).split('&');
+  // If we have a query in the hash.
+  if (loc.hash.indexOf('?') >= 0) {
+    // Remove the hash and split this query into parameters too.
+    query = query.concat(loc.hash.substr(loc.hash.indexOf('?') + 1).split('&'));
+  }
   for (var i = 0; i < query.length; i++) {
     // Decode and store each parameter value.
     parameter = query[i].split('=');