[ios] Fixes crash in Bookmarks scrolling while NewFolder is being edited

- Checks the IndexPath instead of the Cell on canEditRow, the previous method was causing new cells
not to be on edit Mode when the table did was on edit Mode.
- Moves back the editingCell setup to cellForRowAtIndexPath (like legacy) since it was crashing
 on willDisplayCell.
- Creates a test to check the previous case.

Bug: 854185
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ic4f7b27a6a48d48d26a68b9297a4b17e535a542f
Reviewed-on: https://chromium-review.googlesource.com/1112675Reviewed-by: edchin <edchin@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569894}

ios/chrome/browser/ui/bookmarks/bookmark_home_view_controller.mm

@@ -1718,7 +1718,22 @@ const CGFloat kShadowRadius = 12.0f;
   if (item.type == BookmarkHomeItemTypeBookmark) {
     BookmarkHomeNodeItem* nodeItem =
         base::mac::ObjCCastStrict<BookmarkHomeNodeItem>(item);
-    if (!experimental_flags::IsBookmarksUIRebootEnabled()) {
+    if (experimental_flags::IsBookmarksUIRebootEnabled()) {
+      if (nodeItem.bookmarkNode->is_folder() &&
+          nodeItem.bookmarkNode == self.sharedState.editingFolderNode) {
+        TableViewBookmarkFolderCell* tableCell =
+            base::mac::ObjCCastStrict<TableViewBookmarkFolderCell>(cell);
+        // Delay starting edit, so that the cell is fully created. This is
+        // needed when scrolling away and then back into the editingCell,
+        // without the delay the cell will resign first responder before its
+        // created.
+        dispatch_async(dispatch_get_main_queue(), ^{
+          self.sharedState.editingFolderCell = tableCell;
+          [tableCell startEdit];
+          tableCell.textDelegate = self;
+        });
+      }
+    } else {
       BookmarkTableCell* tableCell =
           base::mac::ObjCCastStrict<BookmarkTableCell>(cell);
       if (nodeItem.bookmarkNode == self.sharedState.editingFolderNode) {
@@ -1730,6 +1745,7 @@ const CGFloat kShadowRadius = 12.0f;
         });
       }
     }
+
     // Cancel previous load attempts.
     [self cancelLoadingFaviconAtIndexPath:indexPath];
     // Load the favicon from cache.  If not found, try fetching it from a
@@ -1751,8 +1767,8 @@ const CGFloat kShadowRadius = 12.0f;
 
   // If the cell at |indexPath| is being edited (which happens when creating a
   // new Folder) return NO.
-  if (self.sharedState.editingFolderCell ==
-      [self.tableView cellForRowAtIndexPath:indexPath]) {
+  if ([tableView indexPathForCell:self.sharedState.editingFolderCell] ==
+      indexPath) {
     return NO;
   }
 
@@ -1867,25 +1883,4 @@ const CGFloat kShadowRadius = 12.0f;
   }
 }
 
-- (void)tableView:(UITableView*)tableView
-      willDisplayCell:(UITableViewCell*)cell
-    forRowAtIndexPath:(NSIndexPath*)indexPath {
-  if (experimental_flags::IsBookmarksUIRebootEnabled()) {
-    TableViewItem* item =
-        [self.sharedState.tableViewModel itemAtIndexPath:indexPath];
-    if (item.type == BookmarkHomeItemTypeBookmark) {
-      BookmarkHomeNodeItem* nodeItem =
-          base::mac::ObjCCastStrict<BookmarkHomeNodeItem>(item);
-      if (nodeItem.bookmarkNode->is_folder() &&
-          nodeItem.bookmarkNode == self.sharedState.editingFolderNode) {
-        TableViewBookmarkFolderCell* tableCell =
-            base::mac::ObjCCastStrict<TableViewBookmarkFolderCell>(cell);
-        self.sharedState.editingFolderCell = tableCell;
-        [tableCell startEdit];
-        tableCell.textDelegate = self;
-      }
-    }
-  }
-}
-
 @end

ios/chrome/browser/ui/bookmarks/bookmarks_egtest.mm

@@ -3309,6 +3309,37 @@ id<GREYMatcher> TappableBookmarkNodeWithLabel(NSString* label) {
       assertWithMatcher:grey_nil()];
 }
 
+- (void)testNavigateAwayFromFolderBeingEdited {
+  [BookmarksTestCase setupBookmarksWhichExceedsScreenHeight];
+  [BookmarksTestCase openBookmarks];
+  [BookmarksTestCase openMobileBookmarks];
+
+  // Verify bottom URL is not visible before scrolling to bottom (make sure
+  // setupBookmarksWhichExceedsScreenHeight works as expected).
+  [[EarlGrey selectElementWithMatcher:grey_accessibilityID(@"Bottom URL")]
+      assertWithMatcher:grey_notVisible()];
+
+  // Verify the top URL is visible (isn't covered by the navigation bar).
+  [[EarlGrey selectElementWithMatcher:grey_accessibilityID(@"Top URL")]
+      assertWithMatcher:grey_sufficientlyVisible()];
+
+  // Test new folder could be created.  This verifies bookmarks scrolled to
+  // bottom successfully for folder name editng.
+  NSString* newFolderTitle = @"New Folder";
+  [BookmarksTestCase createNewBookmarkFolderWithFolderTitle:newFolderTitle
+                                                pressReturn:NO];
+
+  // Scroll to top to navigate away from the folder being created.
+  [BookmarksTestCase scrollToTop];
+
+  // Scroll back to the Folder being created.
+  [BookmarksTestCase scrollToBottom];
+
+  // Folder should still be in Edit mode, because of this match for Value.
+  [[EarlGrey selectElementWithMatcher:grey_accessibilityValue(@"New Folder")]
+      assertWithMatcher:grey_notNil()];
+}
+
 - (void)testDeleteSingleFolderNode {
   [BookmarksTestCase setupStandardBookmarks];
   [BookmarksTestCase openBookmarks];