[Autofill] Fixes a bug with the CardUnmaskPromptViewController.

ios/chrome/browser/ui/autofill/card_unmask_prompt_view_bridge.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ios/chrome/browser/ui/autofill/card_unmask_prompt_view_bridge.h"
 
 #include "base/bind.h"
 #include "base/ios/ios_util.h"
 #include "base/location.h"
 #include "base/mac/foundation_util.h"
@@ skipping 188 matching lines @@
   [_verifyButton setTitleTextAttributes:@{
     NSForegroundColorAttributeName : [UIColor lightGrayColor]
   }
                                forState:UIControlStateDisabled];
   [_verifyButton setEnabled:NO];
   self.navigationItem.rightBarButtonItem = _verifyButton;
 }
 
 - (void)viewWillLayoutSubviews {
   [super viewWillLayoutSubviews];
-  NSIndexPath* CVCIndexPath =
-      [self.collectionViewModel indexPathForItem:_CVCItem];
-  CVCCell* CVC = base::mac::ObjCCastStrict<CVCCell>(
-      [self.collectionView cellForItemAtIndexPath:CVCIndexPath]);
-  [self focusInputIfNeeded:CVC];
+  if ([self.collectionViewModel hasItemForItemType:ItemTypeCVC
+                                 sectionIdentifier:SectionIdentifierMain]) {
+    NSIndexPath* CVCIndexPath =
+        [self.collectionViewModel indexPathForItem:_CVCItem];
+    CVCCell* CVC = base::mac::ObjCCastStrict<CVCCell>(
+        [self.collectionView cellForItemAtIndexPath:CVCIndexPath]);
+    [self focusInputIfNeeded:CVC];
+  }
 }
 
 #pragma mark - CollectionViewController
 
 - (void)loadModel {
   [super loadModel];
   CollectionViewModel* model = self.collectionViewModel;
   [model addSectionWithIdentifier:SectionIdentifierMain];
 
   autofill::CardUnmaskPromptController* controller = _bridge->GetController();
@@ skipping 365 matching lines @@
 - (void)collectionView:(UICollectionView*)collectionView
        willDisplayCell:(UICollectionViewCell*)cell
     forItemAtIndexPath:(NSIndexPath*)indexPath {
   CVCCell* CVC = base::mac::ObjCCast<CVCCell>(cell);
   if (CVC) {
     [self focusInputIfNeeded:CVC];
   }
 }
 
 @end