Removes the displayed cell in the ReadingList item

ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm

Index: ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm
diff --git a/ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm b/ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm
index 3d244f4a290b11dd36c653084877baa9ef66b724..856dc459efaa41ef3e4ca41a25d3793de0a04bbb 100644
--- a/ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm
+++ b/ios/chrome/browser/ui/reading_list/reading_list_collection_view_controller.mm
@@ -582,6 +582,9 @@ using ItemsMapByDate = std::multimap<int64_t, ReadingListCollectionViewItem*>;
   if ([items count] != map.size())
     return YES;
 
+  NSMutableArray<ReadingListCollectionViewItem*>* itemsToReconfigure =
+      [NSMutableArray array];
+
   NSInteger index = 0;
   ItemsMapByDate::const_reverse_iterator iterator = map.rbegin();
   for (; iterator != map.rend(); iterator++) {
@@ -589,8 +592,12 @@ using ItemsMapByDate = std::multimap<int64_t, ReadingListCollectionViewItem*>;
         base::mac::ObjCCastStrict<ReadingListCollectionViewItem>(items[index]);
     ReadingListCollectionViewItem* newItem = iterator->second;

[Olivier, 2017/03/28 08:52:07]

If an item is inserted (and index is not synchronized with iterator anymore),
does it reload all items?

[gambard, 2017/03/28 09:43:14]

Yes. It is hard to find a good heuristic to calculate the diff.

     if (oldItem.url == newItem.url) {
-      oldItem.text = newItem.text;
-      oldItem.distillationState = newItem.distillationState;
+      if (![oldItem isEqual:newItem]) {
+        oldItem.text = newItem.text;
+        oldItem.detailText = newItem.detailText;
+        oldItem.distillationState = newItem.distillationState;
+        [itemsToReconfigure addObject:oldItem];
+      }
       if (oldItem.faviconPageURL != newItem.faviconPageURL) {
         [self setItem:oldItem faviconURL:newItem.faviconPageURL];
       }
@@ -600,6 +607,8 @@ using ItemsMapByDate = std::multimap<int64_t, ReadingListCollectionViewItem*>;
     }
     index++;
   }
+  [self reconfigureCellsForItems:itemsToReconfigure
+         inSectionWithIdentifier:sectionIdentifier];
   return NO;
 }