Timeout if website never completes the transaction.

third_party/WebKit/Source/modules/payments/PaymentCompleter.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 PaymentCompleter_h
 #define PaymentCompleter_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "modules/ModulesExport.h"
 #include "platform/heap/GarbageCollected.h"
 
 namespace blink {
 
-enum PaymentComplete {
-    Success,
-    Fail,
-    Unknown
-};
-
 class ScriptState;
 
 class MODULES_EXPORT PaymentCompleter : public GarbageCollectedMixin {
 public:
+    enum PaymentComplete {
+        Success,
+        Fail,
+        Unknown
+    };
+
     virtual ScriptPromise complete(ScriptState*, PaymentComplete result) = 0;
 
 protected:
     virtual ~PaymentCompleter() {}
 };
 
 } // namespace blink
 
 #endif // PaymentCompleter_h