Reject PaymentResponse.complete() promise on error.

third_party/WebKit/Source/modules/payments/PaymentRequest.cpp

 // 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.
 
 #include "modules/payments/PaymentRequest.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/JSONValuesForV8.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
@@ skipping 307 matching lines @@
 ExecutionContext* PaymentRequest::getExecutionContext() const
 {
     return ContextLifecycleObserver::getExecutionContext();
 }
 
 ScriptPromise PaymentRequest::complete(ScriptState* scriptState, PaymentComplete result)
 {
     if (m_completeResolver)
         return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "Already called complete() once"));
 
+    // User has cancelled the transaction while the website was processing it.
+    if (!m_paymentProvider)
+        return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "Request cancelled"));

[Marijn Kruisselbrink, 2016/06/21 20:45:50]

It seems a bit odd that this throws a different exception than what would be
thrown in the (only different by race conditions) situation where the mojo
connection just happens to have closed right after complete() was called (in
that case OnError throws a SyntaxError). But maybe it's that SyntaxError that
doesn't really make sense?

Also is there a corresponding spec bug for this case? Although I'm not quite
clear on how much of the UI behavior is actually part of the spec and how much
is just up to user agents.

[please use gerrit instead, 2016/06/21 21:03:01]

User cancelling the payment request does not appear anywhere in the spec. I will
bring it up with the editors. UI behavior is indeed up to user agents to
determine.

+
     // The payment provider should respond in PaymentRequest::OnComplete().
     m_paymentProvider->Complete(mojom::blink::PaymentComplete(result));
 
     m_completeResolver = ScriptPromiseResolver::create(scriptState);
     return m_completeResolver->promise();
 }
 
 void PaymentRequest::onUpdatePaymentDetails(const ScriptValue& detailsScriptValue)
 {
     if (!m_showResolver || !m_paymentProvider)
@@ skipping 199 matching lines @@
 {
     m_completeResolver.clear();
     m_showResolver.clear();
     m_abortResolver.clear();
     if (m_clientBinding.is_bound())
         m_clientBinding.Close();
     m_paymentProvider.reset();
 }
 
 } // namespace blink