Regressed by
https://codereview.chromium.org/2301833005/

workaround sent out for review.

Assigning to nektar@ for underlying regression.

Line breaks should from at least ChromeVox's perspective and probably most other screen readers work as follows:
- consider leaves that are *text* nodes. Text nodes are nodes who's accessible name is text from the *DOM*. Thus, nodes with roles of static text, line break should be included. However, nodes of other types who's names from are not from contents, should not be considered like divs with an raia label and that are also leaves.
- line breaks, as calculated by the AX module in ui/, should:
provide the index where a line break occurs. If it is a hard line break, the index should contain a new line character. If it is a soft line break, the index should fall on the start of the next line and the client should use affinity to resolve where the caret actually is.

This is marked as a beta blocker for R55 and we are coming up on beta, has any work been started on this?

Yes, https://codereview.chromium.org/2271893002/
But I will not be able to finish it in time.
So, I'll send out a more temporary fix.

 Issue 657428  has been merged into this issue.

Just a heads up that this bug is marked as ReleaseBlock-Beta for R55, and we are looking to promote R55 to beta with the build on Monday evening. 

It looks like the CL has a LGTM on it, if we can land it in the next day and get it merged into Chrome by (optimally) Sunday afternoon we should be able to make the beta RC.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6be580cbb1b4947179978c1c0f2dd9c680a99863

commit 6be580cbb1b4947179978c1c0f2dd9c680a99863
Author: nektar <nektar@chromium.org>
Date: Thu Oct 20 23:07:59 2016

Fixed line start offsets.

Now they indeed refer to the offset at the start of each line. This means that if e.g. the first text node starts a new line, the first offset returned should be 0. Further, the offset equivalent to the text's length should never be returned.
I chose to stick with line start offsets instead of line breaks because what exactly is a line break? The beginning of the line, the end of the previous line or the line break character in between two lines when it exists? And what happens if there is no line break character, i.e. a soft line break?
Line start offsets are less ambiguous.
BUG= 652059 
R=dmazzoni@chromium.org, dtseng@chromium.org
TESTED=automation browsertests, manually with ChromeVox on ChromeOS

Review-Url: https://chromiumcodereview.appspot.com/2437473003
Cr-Commit-Position: refs/heads/master@{#426636}

[modify] https://crrev.com/6be580cbb1b4947179978c1c0f2dd9c680a99863/chrome/test/data/extensions/api_test/automation/tests/tabs/line_start_offsets.js
[modify] https://crrev.com/6be580cbb1b4947179978c1c0f2dd9c680a99863/content/browser/accessibility/accessibility_tree_formatter_blink.cc
[modify] https://crrev.com/6be580cbb1b4947179978c1c0f2dd9c680a99863/ui/accessibility/ax_node.cc
[modify] https://crrev.com/6be580cbb1b4947179978c1c0f2dd9c680a99863/ui/accessibility/ax_node.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b2130a303ca27915ac7abbbefe9f675c582852d2

commit b2130a303ca27915ac7abbbefe9f675c582852d2
Author: David Tseng <dtseng@chromium.org>
Date: Fri Oct 21 17:06:36 2016

Merge to m55: Fixed line start offsets.

Now they indeed refer to the offset at the start of each line. This means that if e.g. the first text node starts a new line, the first offset returned should be 0. Further, the offset equivalent to the text's length should never be returned.
I chose to stick with line start offsets instead of line breaks because what exactly is a line break? The beginning of the line, the end of the previous line or the line break character in between two lines when it exists? And what happens if there is no line break character, i.e. a soft line break?
Line start offsets are less ambiguous.
TBR=nektar@chromium.org
BUG= 652059 
R=dmazzoni@chromium.org, dtseng@chromium.org
TESTED=automation browsertests, manually with ChromeVox on ChromeOS

Review-Url: https://chromiumcodereview.appspot.com/2437473003
Cr-Commit-Position: refs/heads/master@{#426636}
(cherry picked from commit 6be580cbb1b4947179978c1c0f2dd9c680a99863)

Review URL: https://codereview.chromium.org/2439133002 .

Cr-Commit-Position: refs/branch-heads/2883@{#231}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/chrome/test/data/extensions/api_test/automation/tests/tabs/line_start_offsets.js
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/content/browser/accessibility/accessibility_tree_formatter_blink.cc
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/ui/accessibility/ax_node.cc
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/ui/accessibility/ax_node.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b2130a303ca27915ac7abbbefe9f675c582852d2

commit b2130a303ca27915ac7abbbefe9f675c582852d2
Author: David Tseng <dtseng@chromium.org>
Date: Fri Oct 21 17:06:36 2016

Merge to m55: Fixed line start offsets.

Now they indeed refer to the offset at the start of each line. This means that if e.g. the first text node starts a new line, the first offset returned should be 0. Further, the offset equivalent to the text's length should never be returned.
I chose to stick with line start offsets instead of line breaks because what exactly is a line break? The beginning of the line, the end of the previous line or the line break character in between two lines when it exists? And what happens if there is no line break character, i.e. a soft line break?
Line start offsets are less ambiguous.
TBR=nektar@chromium.org
BUG= 652059 
R=dmazzoni@chromium.org, dtseng@chromium.org
TESTED=automation browsertests, manually with ChromeVox on ChromeOS

Review-Url: https://chromiumcodereview.appspot.com/2437473003
Cr-Commit-Position: refs/heads/master@{#426636}
(cherry picked from commit 6be580cbb1b4947179978c1c0f2dd9c680a99863)

Review URL: https://codereview.chromium.org/2439133002 .

Cr-Commit-Position: refs/branch-heads/2883@{#231}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/chrome/test/data/extensions/api_test/automation/tests/tabs/line_start_offsets.js
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/content/browser/accessibility/accessibility_tree_formatter_blink.cc
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/ui/accessibility/ax_node.cc
[modify] https://crrev.com/b2130a303ca27915ac7abbbefe9f675c582852d2/ui/accessibility/ax_node.h

verified on 55.0.2883.30

[Automated comment] removing mislabelled merge-merged-2840