Basic implementation of showing password fill dialog on page load

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 160 matching lines @@
 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 */,
                     base::string16 /* password */)
 
+// Sent when a password form is initially detected and suggestions should be
+// shown. Used by the fill-on-select experiment.
+IPC_MESSAGE_ROUTED2(AutofillMsg_ShowInitialPasswordAccountSuggestions,
+                    int /* key */,
+                    autofill::PasswordFormFillData /* the fill form data */)
+
 // Tells the renderer to find the focused password form (assuming it exists).
 // Renderer is expected to respond with the message
 // |AutofillHostMsg_FocusedPasswordFormFound|.
 IPC_MESSAGE_ROUTED0(AutofillMsg_FindFocusedPasswordForm)
 
 // Tells the renderer to find a focused element, and if it is a password field
 // eligible for generation then to trigger generation by responding to the
 // browser with the message |AutofillHostMsg_ShowPasswordGenerationPopup|.
 IPC_MESSAGE_ROUTED0(AutofillMsg_UserTriggeredGeneratePassword)
 
@@ skipping 148 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)