[Web Payments] Common Payments validation

components/payments/payment_details_validation.h

+// Copyright 2016 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_PAYMENTS_PAYMENT_DETAILS_VALIDATION_H_
+#define COMPONENTS_PAYMENTS_PAYMENT_DETAILS_VALIDATION_H_
+
+#include <string>
+
+#include "components/payments/payment_request.mojom.h"
+
+namespace payments {
+
+bool validatePaymentDetails(const blink::mojom::PaymentDetailsPtr& details,
+                            std::string* error_message);
+
+}  // namespace payments
+
+#endif  // COMPONENTS_PAYMENTS_PAYMENT_DETAILS_VALIDATION_H_