[autofill] Add support for PSL domain matching for password autofill.

components/autofill/common/password_form_fill_data.h

Index: components/autofill/common/password_form_fill_data.h
diff --git a/components/autofill/common/password_form_fill_data.h b/components/autofill/common/password_form_fill_data.h
index 1c6091a80d0f43e19c8ac6a382be129a05606348..878df540d455e306652cff27d08548cbac38f0d1 100644
--- a/components/autofill/common/password_form_fill_data.h
+++ b/components/autofill/common/password_form_fill_data.h
@@ -28,7 +28,11 @@ struct UsernamesCollectionKey {
 // Structure used for autofilling password forms.
 // basic_data identifies the HTML form on the page and preferred username/
 //            password for login, while
-// additional_logins is a list of other matching user/pass pairs for the form.
+// preferred_realm the signon realm of the preferred user/pass pair.
+// additional_logins_passwords is a list of other matching user/pass pairs for
+//                             the form.
+// additional_logins_realms is a list of the realms of other matching user/pass
+//                          for the form.

[Ilya Sherman, 2013/06/06 09:25:35]

I don't quite understand:  Are these supposed to be iterated over in lock-step? 
It seems better to just keep a single collection, but change the type of the map
value to be a struct that contains both the password and the realm.

[nyquist, 2013/06/07 22:51:10]

Done.

 // other_possible_usernames is a list of possible usernames in the case where we
 //     aren't completely sure that the original saved username is correct.
 //     This data is keyed by the saved username/password to ensure uniqueness,
@@ -44,7 +48,9 @@ struct PasswordFormFillData {
                    std::vector<base::string16> > UsernamesCollection;
 
   FormData basic_data;
-  LoginCollection additional_logins;
+  base::string16 preferred_realm;
+  LoginCollection additional_logins_passwords;
+  LoginCollection additional_logins_realms;
   UsernamesCollection other_possible_usernames;
   bool wait_for_username;
   PasswordFormFillData();