Fix unhandled SecurityException in iOS password_controller

ios/chrome/browser/passwords/resources/password_controller.js

Index: ios/chrome/browser/passwords/resources/password_controller.js
diff --git a/ios/chrome/browser/passwords/resources/password_controller.js b/ios/chrome/browser/passwords/resources/password_controller.js
index 6599b257827cc6c490f1cc3509579003eab5709a..7c4b8b9c65b8ce48f47c57169444776e78348760 100644
--- a/ios/chrome/browser/passwords/resources/password_controller.js
+++ b/ios/chrome/browser/passwords/resources/password_controller.js
@@ -214,7 +214,12 @@ if (__gCrWeb && !__gCrWeb['fillPasswordForm']) {
    */
   __gCrWeb.fillPasswordFormWithData =
       function(formData, username, password, win, opt_normalizedOrigin) {
-    var doc = win.document;
+    var doc = null;
+
+    try {
+      doc = win.document;
+    } catch(e) {
+    }
 
     // If unable to read the 'document' property from a frame in a different
     // origin, do nothing.