[ios] Disabling failing GridViewControllerTest.ReplaceScrolledOffScreenCell

Now failing on iOS 12 and 14.

Bug: 1104872
Change-Id: I53183dc4f9e8559e02ff49009a0ea97037d5368e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2445111
Auto-Submit: David Jean <djean@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813106}

ios/chrome/browser/ui/tab_grid/grid/grid_view_controller_unittest.mm

@@ -183,7 +183,7 @@ TEST_F(GridViewControllerTest, MoveUnselectedItem) {
 
 // Tests that |-replaceItemID:withItem:| does not crash when updating an item
 // that is scrolled offscreen.
-TEST_F(GridViewControllerTest, ReplaceScrolledOffScreenCell) {
+TEST_F(GridViewControllerTest, DISABLED_ReplaceScrolledOffScreenCell) {
   // TODO(crbug.com/1104872): On iOS 14 iPhone X, visibleCellsCount is always
   // equal to the total number of cells, so the while loop below never
   // terminates.