[Autofill] Fill fields that have an autocomplete attributes even if not in a form.

components/autofill/core/common/form_data.h

Index: components/autofill/core/common/form_data.h
diff --git a/components/autofill/core/common/form_data.h b/components/autofill/core/common/form_data.h
index a406ccbd3d2c70958df8187e20673a1c0f92cf5c..6014c14fcd04642276833793e26513285d340856 100644
--- a/components/autofill/core/common/form_data.h
+++ b/components/autofill/core/common/form_data.h
@@ -32,8 +32,10 @@ struct FormData {
   GURL origin;
   // The action target of the form.
   GURL action;
-  // true if this form is a form tag.
+  // True if this form is a form tag.
   bool is_form_tag;
+  // True if the form is made of unowned fields in a non checkout flow.
+  bool is_formless_checkout;
   // A vector of all the input fields in the form.
   std::vector<FormFieldData> fields;
 };