Prepare the infrastructure for password overrides.

components/autofill/core/common/password_form_field_predictions.h

Index: components/autofill/core/common/password_form_field_predictions.h
diff --git a/components/autofill/core/common/password_form_field_predictions.h b/components/autofill/core/common/password_form_field_predictions.h
new file mode 100644
index 0000000000000000000000000000000000000000..cc2f468341ebd254e4b5a985e500943b87cc841d
--- /dev/null
+++ b/components/autofill/core/common/password_form_field_predictions.h
@@ -0,0 +1,26 @@
+// Copyright 2015 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.
+
+#ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_PASSWORD_FORM_FIELD_PREDICTIONS_H_
+#define COMPONENTS_AUTOFILL_CORE_BROWSER_PASSWORD_FORM_FIELD_PREDICTIONS_H_
+
+#include <map>
+
+#include "components/autofill/core/common/form_field_data.h"
+
+namespace autofill {
+
+enum PasswordFormFieldPredictionType {
+  PREDICTION_USERNAME,

[vabr (Chromium), 2015/05/27 13:31:51]

Would it make sense to use ServerFieldType instead?

[msramek, 2015/05/27 14:38:35]

I wanted to give GetPasswordForm() a more explicit input, but it could work
directly with ServerFieldType too. I don't have such a strong opinion on this.

However, it cannot be done directly, as ServerFieldType is in browser/, and this
needs to stay in common/ (these messages are sent from renderer to browser).

[vabr (Chromium), 2015/05/28 07:53:32]

Acknowledged, can stay as it is. Would you consider putting in a code comment
explaining that this does not use ServerFieldType, because that type is
currently in browser/ instead of common/?

[msramek, 2015/05/28 19:36:48]

Done.

+  PREDICTION_CURRENT_PASSWORD,
+  PREDICTION_NEW_PASSWORD,
+  PREDICTION_MAX = PREDICTION_NEW_PASSWORD
+};
+
+using PasswordFormFieldPredictions =
+    std::map<PasswordFormFieldPredictionType, FormFieldData>;

[Ilya Sherman, 2015/05/27 18:21:50]

nit: I'd prefer to avoid this typedef/using stmt entirely.  However, if you do
keep it, please name the type "PasswordFormFieldPredictionMap".  "PredictionMap"
indicates a map, whereas a simply plural "Predictions", by convention, indicates
a vector or other type of list.

[msramek, 2015/05/28 19:36:48]

I'd prefer not to add a file for so little content either, but currently this
seems like the most reasonable approach. I'll keep it in mind; eventually, we
might want to give even more autofill information to password manager and then
we'll definitely want to reuse ServerFieldType.

Renamed to Map.

+
+}  // namespace autofill
+
+#endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_PASSWORD_FORM_FIELD_PREDICTIONS_H_