[Payment Request] Simplifies VC's logic to decide if an item is selectable

ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm

Index: ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm
diff --git a/ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm b/ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm
index 01a8b22fab6b17a32ac0ce778676b29c3b6a5f06..e25258d5fecdd919c4be7631c379a7f6a52bb5cc 100644
--- a/ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm
+++ b/ios/chrome/browser/ui/payments/shipping_address_selection_coordinator.mm
@@ -105,7 +105,7 @@ const int64_t kDelegateNotificationDelayInNanoSeconds = 0.2 * NSEC_PER_SEC;
 
 #pragma mark - PaymentRequestSelectorViewControllerDelegate
 
-- (void)paymentRequestSelectorViewController:
+- (BOOL)paymentRequestSelectorViewController:
             (PaymentRequestSelectorViewController*)controller
                         didSelectItemAtIndex:(NSUInteger)index {
   CollectionViewItem<PaymentsIsSelectable>* selectedItem =
@@ -121,8 +121,10 @@ const int64_t kDelegateNotificationDelayInNanoSeconds = 0.2 * NSEC_PER_SEC;
     // Update the data source with the selection.
     self.mediator.selectedItemIndex = index;
     [self delayedNotifyDelegateOfSelection:shippingProfile];
+    return YES;
   } else {
     [self startAddressEditCoordinatorWithAddress:shippingProfile];
+    return NO;
   }
 }
 
@@ -158,13 +160,20 @@ const int64_t kDelegateNotificationDelayInNanoSeconds = 0.2 * NSEC_PER_SEC;
   // Update the data source with the new data.
   [self.mediator loadItems];
 
+  const std::vector<autofill::AutofillProfile*>& shippingProfiles =
+      self.paymentRequest->shipping_profiles();
+  const auto position =
+      std::find(shippingProfiles.begin(), shippingProfiles.end(), address);
+  DCHECK(position != shippingProfiles.end());
+
+  // Mark the edited item as complete meaning all required information has been
+  // filled out.
+  CollectionViewItem<PaymentsIsSelectable>* editedItem =
+      self.mediator.selectableItems[position - shippingProfiles.begin()];
+  editedItem.complete = YES;
+
   if (![self.viewController isEditing]) {
     // Update the data source with the selection.
-    const std::vector<autofill::AutofillProfile*>& shippingProfiles =
-        self.paymentRequest->shipping_profiles();
-    const auto position =
-        std::find(shippingProfiles.begin(), shippingProfiles.end(), address);
-    DCHECK(position != shippingProfiles.end());
     self.mediator.selectedItemIndex = position - shippingProfiles.begin();
   }
 
@@ -174,12 +183,6 @@ const int64_t kDelegateNotificationDelayInNanoSeconds = 0.2 * NSEC_PER_SEC;
   [self.addressEditCoordinator stop];
   self.addressEditCoordinator = nil;
 
-  // Mark the item as complete meaning all required information has been
-  // filled out.
-  CollectionViewItem<PaymentsIsSelectable>* selectedItem =
-      self.mediator.selectableItems[self.mediator.selectedItemIndex];
-  selectedItem.complete = YES;
-
   if (![self.viewController isEditing]) {
     // Inform |self.delegate| that |address| has been selected.
     [self.delegate shippingAddressSelectionCoordinator:self