Autofill: Set requirements for number of recognized fields in an autofillable form

components/autofill/content/common/autofill_messages.h

 // 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.
 
 // Multiply-included message file, hence no include guard.
 
 #include <string>
 #include <vector>
 
 #include "base/strings/string16.h"
@@ skipping 190 matching lines @@
 // Autofill messages sent from the renderer to the browser.
 
 // TODO(creis): check in the browser that the renderer actually has permission
 // for the URL to avoid compromised renderers talking to the browser.
 
 // Notification that there has been a user gesture.
 IPC_MESSAGE_ROUTED0(AutofillHostMsg_FirstUserGestureObserved)
 
 // Notification that forms have been seen that are candidates for
 // filling/submitting by the AutofillManager.
-IPC_MESSAGE_ROUTED2(AutofillHostMsg_FormsSeen,
+// If there is no unowned form, the index is size of |forms|.
+IPC_MESSAGE_ROUTED3(AutofillHostMsg_FormsSeen,
                     std::vector<autofill::FormData> /* forms */,
+                    size_t /* unowned_form_index */,
                     base::TimeTicks /* timestamp */)
 
 // Notification that password forms have been seen that are candidates for
 // filling/submitting by the password manager.
 IPC_MESSAGE_ROUTED1(AutofillHostMsg_PasswordFormsParsed,
                     std::vector<autofill::PasswordForm> /* forms */)
 
 // Notification that initial layout has occurred and the following password
 // forms are visible on the page (e.g. not set to display:none.), and whether
 // all frames in the page have been rendered.
@@ skipping 87 matching lines @@
     int /* key */,
     base::i18n::TextDirection /* text_direction */,
     base::string16 /* username typed by user */,
     int /* options bitmask of autofill::ShowPasswordSuggestionsOptions */,
     gfx::RectF /* input field bounds, window-relative */)
 
 // Inform browser of data list values for the curent field.
 IPC_MESSAGE_ROUTED2(AutofillHostMsg_SetDataList,
                     std::vector<base::string16> /* values */,
                     std::vector<base::string16> /* labels */)