Warn web developer on missing favicon for PaymentRequest UI.

third_party/WebKit/Source/modules/payments/PaymentRequest.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 PaymentRequest_h
 #define PaymentRequest_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "components/payments/mojom/payment_request.mojom-blink.h"
@@ skipping 91 matching lines @@
   // payments::mojom::blink::PaymentRequestClient:
   void OnShippingAddressChange(
       payments::mojom::blink::PaymentAddressPtr) override;
   void OnShippingOptionChange(const String& shipping_option_id) override;
   void OnPaymentResponse(payments::mojom::blink::PaymentResponsePtr) override;
   void OnError(payments::mojom::blink::PaymentErrorReason) override;
   void OnComplete() override;
   void OnAbort(bool aborted_successfully) override;
   void OnCanMakePayment(
       payments::mojom::blink::CanMakePaymentQueryResult) override;
+  void WarnNoFavicon() override;
 
   void OnCompleteTimeout(TimerBase*);
 
   // Clears the promise resolvers and closes the Mojo connection.
   void ClearResolversAndCloseMojoConnection();
 
   PaymentOptions options_;
   Member<PaymentAddress> shipping_address_;
   String id_;
   String shipping_option_;
   String shipping_type_;
   Member<ScriptPromiseResolver> show_resolver_;
   Member<ScriptPromiseResolver> complete_resolver_;
   Member<ScriptPromiseResolver> abort_resolver_;
   Member<ScriptPromiseResolver> can_make_payment_resolver_;
   payments::mojom::blink::PaymentRequestPtr payment_provider_;
   mojo::Binding<payments::mojom::blink::PaymentRequestClient> client_binding_;
   TaskRunnerTimer<PaymentRequest> complete_timer_;
 };
 
 }  // namespace blink
 
 #endif  // PaymentRequest_h