[WebPayments] Start populating the Payment Sheet.

chrome/browser/payments/payment_request_impl.h

Index: chrome/browser/payments/payment_request_impl.h
diff --git a/chrome/browser/payments/payment_request_impl.h b/chrome/browser/payments/payment_request_impl.h
index fe3b6e73a9e929fb734313cd71317f88d8584ab9..d87d8bee3ec6c8b6875ebe07b8b7b12334f2d246 100644
--- a/chrome/browser/payments/payment_request_impl.h
+++ b/chrome/browser/payments/payment_request_impl.h
@@ -34,6 +34,7 @@ class PaymentRequestImpl : payments::mojom::PaymentRequest,
 
   void Cancel();
   void OnError();
+  payments::mojom::PaymentDetails* details() { return details_.get(); }
 
   content::WebContents* web_contents() { return web_contents_; }
 
@@ -44,6 +45,7 @@ class PaymentRequestImpl : payments::mojom::PaymentRequest,
   content::WebContents* web_contents_;
   mojo::Binding<payments::mojom::PaymentRequest> binding_;
   payments::mojom::PaymentRequestClientPtr client_;
+  payments::mojom::PaymentDetailsPtr details_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestImpl);
 };