Reload the Most Visited section when it changes

ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm

Index: ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm
diff --git a/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm b/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm
index f5cebf7a5936bc8170a99169ae2ff2e3fde59a79..da6e94426458f80f877d0084a95ac6a954b4da28 100644
--- a/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm
+++ b/ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm
@@ -221,7 +221,33 @@ const CGFloat kNumberOfMostVisitedLines = 2;
 }
 
 - (void)reloadSection:(ContentSuggestionsSectionInformation*)sectionInfo {
-  // TODO(crbug.com/707754): implement this method.
+  CSCollectionViewModel* model =
+      self.collectionViewController.collectionViewModel;
+  SectionIdentifier sectionIdentifier = SectionIdentifierForInfo(sectionInfo);
+
+  if (![model hasSectionForSectionIdentifier:sectionIdentifier]) {
+    [self.collectionViewController
+        addSuggestions:[self.dataSource itemsForSectionInfo:sectionInfo]
+         toSectionInfo:sectionInfo];
+    return;
+  }
+
+  NSInteger section = [model sectionForSectionIdentifier:sectionIdentifier];
+
+  NSMutableArray* oldItems = [NSMutableArray array];
+  NSInteger numberOfItems = [model numberOfItemsInSection:section];
+  for (NSInteger i = 0; i < numberOfItems; i++) {
+    [oldItems addObject:[NSIndexPath indexPathForItem:i inSection:section]];
+  }
+  [self.collectionViewController
+                   collectionView:self.collectionViewController.collectionView
+      willDeleteItemsAtIndexPaths:oldItems];
+
+  [self addSuggestionsToModel:[self.dataSource itemsForSectionInfo:sectionInfo]
+              withSectionInfo:sectionInfo];
+
+  [self.collectionViewController.collectionView
+      reloadSections:[NSIndexSet indexSetWithIndex:section]];
 }
 
 - (void)faviconAvailableForItem:(CollectionViewItem<SuggestedContent>*)item {