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

components/autofill/content/renderer/password_autofill_agent.cc

Index: components/autofill/content/renderer/password_autofill_agent.cc
diff --git a/components/autofill/content/renderer/password_autofill_agent.cc b/components/autofill/content/renderer/password_autofill_agent.cc
index eb2e06dbe78683c9c03c13020eb30d85bad58718..a70a86a89b787bda8ae5340b4877aac3ea086b19 100644
--- a/components/autofill/content/renderer/password_autofill_agent.cc
+++ b/components/autofill/content/renderer/password_autofill_agent.cc
@@ -967,6 +967,7 @@ bool PasswordAutofillAgent::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(AutofillMsg_SetLoggingState, OnSetLoggingState)
     IPC_MESSAGE_HANDLER(AutofillMsg_AutofillUsernameDataReceived,
                         OnAutofillUsernameDataReceived)
+    IPC_MESSAGE_HANDLER(AutofillMsg_ForceSavePassword, OnForceSavePassword)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -1241,6 +1242,20 @@ void PasswordAutofillAgent::OnAutofillUsernameDataReceived(
   form_predictions_ = predictions;
 }
 
+void PasswordAutofillAgent::OnForceSavePassword() {
+  blink::WebElement element = render_frame()->GetFocusedElement();
+
+  DCHECK(!element.isNull());
+  DCHECK(element.hasHTMLTagName("input"));

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

optional: Consider adding
<< element.tagName()
to the DCHECK for more information in case of failure.

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

Done.

+
+  blink::WebInputElement input = element.to<blink::WebInputElement>();
+  DCHECK(input.isPasswordField());
+
+  ProvisionallySavePassword(input.form(), RESTRICTION_NONE);

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

Why do we need to provisionally save the password, when we send the credentials
to the browser on the next line?

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

Here, ProvisionallySavePassword() is used to transform WebFormElement into
PasswordForm, also applying autofill hints that this class got in
OnAutofillUsernameDataReceived.

The fact that the result is stored in provisionally_saved_form_ doesn't seem to
have any side-effects, especially because PasswordManager is indeed going to
offer to save that form after the callback from this method.

However, now that we changed the name of the method so that it doesn't refer to
force-saving, it will be of course cleaner if we just call CreatePasswordForm
instead.

[vabr (Chromium), 2015/05/29 06:48:50]

Acknowledged.

+  Send(new AutofillHostMsg_PasswordFormForceSaveRequested(
+      routing_id(), *provisionally_saved_form_));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // PasswordAutofillAgent, private: