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

components/autofill/content/renderer/password_form_conversion_utils.cc

Index: components/autofill/content/renderer/password_form_conversion_utils.cc
diff --git a/components/autofill/content/renderer/password_form_conversion_utils.cc b/components/autofill/content/renderer/password_form_conversion_utils.cc
index 3918ef2d375ce8f657ece8faca4549277cc0827c..928fb81f72e26ccac25621a734dac764e059dc4f 100644
--- a/components/autofill/content/renderer/password_form_conversion_utils.cc
+++ b/components/autofill/content/renderer/password_form_conversion_utils.cc
@@ -216,10 +216,7 @@ void GetPasswordForm(const WebFormElement& form,
   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;
 
@@ -291,4 +288,11 @@ scoped_ptr<PasswordForm> CreatePasswordForm(
   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