It's already defined in payment_request.mojom but it isn't exposed in js api.

Ah, great.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/11456cf3138b836726da2975e75f44005de2a266

commit 11456cf3138b836726da2975e75f44005de2a266
Author: jinho.bang <jinho.bang@samsung.com>
Date: Mon Jun 06 17:49:48 2016

PaymentRequest: Provide shippingAddress in PaymentResponse.

The shippingAddress attribute was already added by this issue[1] but current
implementation isn't supporting the attribute yet. So, we should provide the
attribute in PaymentResponse.

[1] https://github.com/w3c/browser-payment-api/pull/139

BUG= 617194 

Review-Url: https://codereview.chromium.org/2038333002
Cr-Commit-Position: refs/heads/master@{#398058}

[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/Source/modules/payments/PaymentRequestTest.cpp
[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/Source/modules/payments/PaymentResponse.cpp
[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/Source/modules/payments/PaymentResponse.h
[modify] https://crrev.com/11456cf3138b836726da2975e75f44005de2a266/third_party/WebKit/Source/modules/payments/PaymentResponse.idl