Add a basic functionality to the force-saving menu item.

components/autofill/content/common/autofill_messages.h

Index: components/autofill/content/common/autofill_messages.h
diff --git a/components/autofill/content/common/autofill_messages.h b/components/autofill/content/common/autofill_messages.h
index 4c3ec108c7c26621c2dbda6e0362080c3a723184..4c154843103bece13fb3f8699e15d1b8d34ca727 100644
--- a/components/autofill/content/common/autofill_messages.h
+++ b/components/autofill/content/common/autofill_messages.h
@@ -187,6 +187,10 @@ IPC_MESSAGE_ROUTED2(AutofillMsg_PreviewPasswordSuggestion,
                     base::string16 /* username */,
                     base::string16 /* password */)
 
+// Tells the renderer to find the focused password field, so that the password
+// can be saved.

[vabr (Chromium), 2015/05/28 19:41:23]

Perhaps rather than "so that the password can be saved" mention that the
renderer is expected to answer with
AutofillHostMsg_PasswordFormForceSaveRequested.

The current formulation makes it unclear what else needs to be done to save the
password, and saving the password is not a part of the expected renderer
response.

[msramek, 2015/05/28 20:28:28]

Done.

+IPC_MESSAGE_ROUTED0(AutofillMsg_ForceSavePassword)

[vabr (Chromium), 2015/05/28 19:41:23]

Also, the name of the message, and the associated PasswordAutofillAgent handler,
is misleading. There is no (non-provisional) saving involved, just locating the
focussed form. Please reflect that in the name.

[msramek, 2015/05/28 20:28:28]

Done.

+
 // Tells the renderer that this password form is not blacklisted.  A form can
 // be blacklisted if a user chooses "never save passwords for this site".
 IPC_MESSAGE_ROUTED1(AutofillMsg_FormNotBlacklisted,
@@ -338,3 +342,8 @@ IPC_MESSAGE_ROUTED5(
 IPC_MESSAGE_ROUTED2(AutofillHostMsg_SetDataList,
                     std::vector<base::string16> /* values */,
                     std::vector<base::string16> /* labels */)
+
+// Inform the browser which password form contains the focused password element
+// and should be saved.
+IPC_MESSAGE_ROUTED1(AutofillHostMsg_PasswordFormForceSaveRequested,
+                    autofill::PasswordForm)