PaymentRequest: Introduce PaymentDetailsInit and PaymentDetailsUpdate.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
index ca53cbcf63dd9f831990019556b106b7a20b6b33..9d8996ea903acf7e325603c0cb35d7ae94efe054 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/payments/PaymentRequestImpl.java
@@ -735,15 +735,20 @@ public class PaymentRequestImpl
                     details.total.amount.currencySystem, Locale.getDefault());
         }
 
-        // Total is never pending.
-        LineItem uiTotal = new LineItem(details.total.label,
-                mCurrencyFormatter.getFormattedCurrencyCode(),
-                mCurrencyFormatter.format(details.total.amount.value), /* isPending */ false);
+        if (details.total != null) {
+            mRawTotal = details.total;
+        }
+
+        if (mRawTotal != null) {

[please use gerrit instead, 2017/03/27 14:00:05]

Please remove the lines 740-742. That should make the code simpler without
changing the logic.

[zino, 2017/03/27 14:47:47]

Done.

[please use gerrit instead, 2017/03/27 14:59:39]

I'm so sorry. I think you original code was actually correctly handling the case
of updateWith() called without "total", but with "displayItems". My suggestion
was wrong. Please bring back the lines 740-742 :-(...

[zino, 2017/03/27 15:05:55]

Oh, right :) Thanks!

+            // Total is never pending.
+            LineItem uiTotal = new LineItem(mRawTotal.label,
+                    mCurrencyFormatter.getFormattedCurrencyCode(),
+                    mCurrencyFormatter.format(mRawTotal.amount.value), /* isPending */ false);
 
-        List<LineItem> uiLineItems = getLineItems(details.displayItems, mCurrencyFormatter);
+            List<LineItem> uiLineItems = getLineItems(details.displayItems, mCurrencyFormatter);
 
-        mUiShoppingCart = new ShoppingCart(uiTotal, uiLineItems);
-        mRawTotal = details.total;
+            mUiShoppingCart = new ShoppingCart(uiTotal, uiLineItems);
+        }
         mRawLineItems = Collections.unmodifiableList(Arrays.asList(details.displayItems));
 
         mUiShippingOptions = getShippingOptions(details.shippingOptions, mCurrencyFormatter);