[Password Generation] Run the form classifier only if AutofillMetadata is enabled

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 150 matching lines @@
 
 // Sets the currently selected node's value to be the given data list value.
 IPC_MESSAGE_ROUTED1(AutofillMsg_AcceptDataListSuggestion,
                     base::string16 /* accepted data list value */)
 
 // Tells the renderer to populate the correct password fields with this
 // generated password.
 IPC_MESSAGE_ROUTED1(AutofillMsg_GeneratedPasswordAccepted,
                     base::string16 /* generated_password */)
 
+// Tells the renderer to enable the form classifier.
+IPC_MESSAGE_ROUTED0(AutofillMsg_AllowToRunFormClassifier)
+
 // Tells the renderer to fill the username and password with with given
 // values.
 IPC_MESSAGE_ROUTED2(AutofillMsg_FillPasswordSuggestion,
                     base::string16 /* username */,
                     base::string16 /* password */)
 
 // Tells the renderer to preview the username and password with the given
 // values.
 IPC_MESSAGE_ROUTED2(AutofillMsg_PreviewPasswordSuggestion,
                     base::string16 /* username */,
@@ skipping 172 matching lines @@
 // 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 */)
 
 // Inform the browser which password form is currently focused, as a response
 // to the |AutofillMsg_FindFocusedPasswordForm| request. If no password form
 // is focused, the response will contain an empty |autofill::PasswordForm|.
 IPC_MESSAGE_ROUTED1(AutofillHostMsg_FocusedPasswordFormFound,
                     autofill::PasswordForm)