Also reproduces with ChromeVox per steps above

Google Chrome	69.0.3497.35 (Official Build) dev (64-bit)
Firmware Version	Google_Lulu.6301.136.57

Disambiguation: 
Bug 854312 is about all of the confusing text spoken by screen reader
 Bug 854345  is about incorrect indexes within that text for Bookmarks folders
Bug 854362 is about incorrect indexes for bookmarks within folders 

The 'treeitem' role is inside of a 'navigation' rather than a 'tree' - I wonder if that affects index computation.

Ah - actually, it's this: https://cs.chromium.org/chromium/src/third_party/blink/renderer/modules/accessibility/ax_node_object.cc?type=cs&sq=package:chromium&g=0&l=1451

Either we need to skip over groups while computing the index, or ensure groups are nested under treeitems and not between them (like this example https://www.w3.org/TR/wai-aria-practices-1.1/examples/treeview/treeview-2/treeview-2a.html).

If we do the latter, https://cs.chromium.org/chromium/src/chrome/browser/resources/md_bookmarks/folder_node.html?type=cs&sq=package:chromium&g=0&l=107 is probably a good place to start.

+dmazzoni/dtseng - any thoughts on which of the two options I outline above would be preferable?

i.e. 
1) skip over "group" role elements when computing indexes of treeitems; or
2) nest "group" role element under treeitem role element in the bookmarks-folder-node element

I feel like (1) is more general

We have a role=navigation which then has children mixing role=treeitem and role=group
Our treeitems then contain groups which further contain treeitems and groups.

ARIA says that we must nest treeitem within either tree or group, but we are nesting it within navigation
"Authors MUST ensure elements with role treeitem are contained in, or owned by, an element with the role group or tree."
https://www.w3.org/TR/wai-aria/#treeitem

I'm going to change the top level item from navigation to treeitem (possibly with a navigation parent, I'll try find other examples).

Using aria-owns seems to correctly fix the nesting of treeitems and groups, so I will add appropriate ownership relations.

The current menu aria roles come from the work on https://bugs.chromium.org/p/chromium/issues/detail?id=735808

I have a pending CR up for review which uses aria-owns to reparent the descendants under the folder, which better matches the semantics of the folder nesting.
This now generates correct indices \o/

I have also changed the top level div from role=navigation to role=tree as I think is required by ARIA.

https://chromium-review.googlesource.com/c/chromium/src/+/1238756

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/adf5b6561bda9b53d4067b12b51ef34501b0e54e

commit adf5b6561bda9b53d4067b12b51ef34501b0e54e
Author: Chris Hall <chrishall@chromium.org>
Date: Fri Sep 28 07:38:26 2018

Bookmarks folder navigation tree correcting indices.

This change corrects the accessibility semantics of the bookmarks folder
navigation tree.

Before this change, the indices on the bookmark folder items were
incorrectly always being read out as '1 of 1' even when there were multiple
items within the menu, this was because each role='treeitem' was followed by
a role='group' sibling.

This change uses aria-owns to reparent the descendents role='group' under the
containing folder, which more closesly matches the semantic meaning of
the nested folders. Now indicies are read out correctly as '1 of 2' or
similar.

This also changes the top level role from 'navigation' to 'tree' as aria
requires that every 'treeitem' is within either a 'tree' or 'group'.


Change-Id: I58ade626e8df6a7bd87be32d05d9d86679bc6200
Bug:  854345 
Reviewed-on: https://chromium-review.googlesource.com/1238756
Commit-Queue: Chris Hall <chrishall@chromium.org>
Reviewed-by: calamity <calamity@chromium.org>
Reviewed-by: Alice Boxhall <aboxhall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595010}
[modify] https://crrev.com/adf5b6561bda9b53d4067b12b51ef34501b0e54e/chrome/browser/resources/md_bookmarks/app.html
[modify] https://crrev.com/adf5b6561bda9b53d4067b12b51ef34501b0e54e/chrome/browser/resources/md_bookmarks/folder_node.html

That change should gives me indices in my testing on ChromeOS and ChromeVox

Fixed as of 71.0.3578.44 (Official Build) beta (64-bit) (cohort: Beta)