Show modified total price for payment instruments.

chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java
index b2b5b9d17c571cb1eb6f19dfb59fcbf87f34873e..f4d430cadc6eb6308a8de7c7688df5965c0923ec 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentInstrument.java
@@ -14,6 +14,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import javax.annotation.Nullable;
+
 /**
  * The base class for a single payment instrument, e.g., a credit card.
  */
@@ -48,6 +50,15 @@ public abstract class PaymentInstrument extends PaymentOption {
     }
 
     /**
+     * Sets the modified total for this payment instrument.
+     *
+     * @param modifiedTotal The new modified total to use.
+     */
+    public void setModifiedTotal(@Nullable String modifiedTotal) {
+        updateTertiarylabel(modifiedTotal);
+    }
+
+    /**
      * Returns a set of payment method names for this instrument, e.g., "visa" or
      * "mastercard" in basic card payments:
      * https://w3c.github.io/webpayments-methods-card/#method-id