[Payments] Implement web payment app manifest

content/public/browser/stored_payment_app.cc

Index: content/public/browser/stored_payment_app.cc
diff --git a/content/public/browser/stored_payment_app.cc b/content/public/browser/stored_payment_app.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3ba73d28993e6ab05a90a6af7414441b7f401733
--- /dev/null
+++ b/content/public/browser/stored_payment_app.cc
@@ -0,0 +1,13 @@
+// Copyright 2017 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.
+
+#include "content/public/browser/stored_payment_app.h"
+
+namespace content {
+
+StoredPaymentApp::StoredPaymentApp() = default;
+
+StoredPaymentApp::~StoredPaymentApp() = default;
+
+}  // namespace content