[Web Payments] Add inline items to the Order Summary section.

components/payments/content/payment_request.h

Index: components/payments/content/payment_request.h
diff --git a/components/payments/content/payment_request.h b/components/payments/content/payment_request.h
index 18d3f94229b3c6e85ff5fbc602fb4e6f58a1725c..6f918e8dc6de461928c27036dbfa28c674b57891 100644
--- a/components/payments/content/payment_request.h
+++ b/components/payments/content/payment_request.h
@@ -86,6 +86,10 @@ class PaymentRequest : payments::mojom::PaymentRequest {
       const std::string& currency_system,
       const std::string& locale_name);
 
+  // Uses CurrencyFormatter to format |amount| with the currency symbol for this
+  // request's currency.
+  base::string16 GetFormattedCurrencyAmount(const std::string& amount);
+
   // Returns the appropriate Autofill Profiles for this user. On the first
   // invocation of either getter, the profiles are fetched from the
   // PersonalDataManager; on subsequent invocations, a cached version is