[Password Manager] Use XHR completion as a possible signal for form submission

components/autofill/content/renderer/password_form_conversion_utils.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/autofill/content/renderer/password_form_conversion_utils.h"
 
 #include "base/strings/string_util.h"
 #include "components/autofill/content/renderer/form_autofill_util.h"
 #include "components/autofill/core/common/password_form.h"
 #include "third_party/WebKit/public/platform/WebString.h"
@@ skipping 198 matching lines @@
         }
       }
     }
     password_form->username_value = username_value;
   }
 
   // Get the document URL
   GURL full_origin(form.document().url());
 
   // Calculate the canonical action URL
-  WebString action = form.action();
-  if (action.isNull())
-    action = WebString(""); // missing 'action' attribute implies current URL
-  GURL full_action(form.document().completeURL(action));
+  GURL full_action = GetCanonicalActionURL(form);
   if (!full_action.is_valid())
     return;
 
   WebInputElement password;
   WebInputElement new_password;
   if (!LocateSpecificPasswords(passwords, &password, &new_password))
     return;
 
   // We want to keep the path but strip any authentication data, as well as
   // query and ref portions of URL, for the form action and form origin.
@@ skipping 51 matching lines @@
   WebFormElementToFormData(web_form,
                            blink::WebFormControlElement(),
                            REQUIRE_NONE,
                            EXTRACT_NONE,
                            &password_form->form_data,
                            NULL /* FormFieldData */);
 
   return password_form.Pass();
 }
 
+GURL GetCanonicalActionURL(const WebFormElement& form) {
+  WebString action = form.action();
+  if (action.isNull())
+    action = WebString(""); // missing 'action' attribute implies current URL
+  return GURL(form.document().completeURL(action));
+}
+
 }  // namespace autofill