Able to reproduce the issue on the reported chrome 68.0.3440.1,latest canary 69.0.3453.0 also on latest stable 67.0.3396.79 using Windows10,Mac OS10.13.3 ,Ubuntu14.04.Below is the bisect information for same.

Bisect Info:
================
Good build: 66.0.3336.0
Bad build: 66.0.3336.0

You are probably looking for a change made after 534186 (known good), but no later than 534200 (first known bad).

CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/5685d4cddd5a7e36bb837a483169a88971163208..dd394d24f61f8969cdfaaa338bcac9511744de30

Reviewed-on:  https://chromium-review.googlesource.com/888543

Suspecting same from change log.

@wutao:Please confirm the issue and help in re-assigning if it is not related to your change.

Thanks!

+msw@, FYI.

StyledLable is using base::i18n::IsRTL() to determine RTL [1], which is using  GetTextDirectionForLocaleInStartUp() [2], which calss GetForcedTextDirection() uses the flag force-ui-direction [3].


[1] https://cs.chromium.org/chromium/src/base/i18n/rtl.cc?l=153&rcl=401867afab6dfa267f75d127bc047c6e62f6899c

[2] https://cs.chromium.org/chromium/src/base/i18n/rtl.cc?l=187&rcl=401867afab6dfa267f75d127bc047c6e62f6899c

[3] https://cs.chromium.org/chromium/src/base/i18n/rtl.cc?l=165&rcl=401867afab6dfa267f75d127bc047c6e62f6899c

Maybe the Label.cc does the RTL flip again [1].

[1] https://cs.chromium.org/chromium/src/ui/views/controls/label.cc?l=143&rcl=92e72e36772a24a743352575aed8ba2a06e39e03

msw@, I do not see we change the direction of text in our StyledLable cl mentioned in the bug. It is handled by underlining class Label.cc.

Perhaps the logic in StyledLabel::AdvanceOneLine() or HorizontalAdjustment() is wrong:
https://cs.chromium.org/chromium/src/ui/views/controls/styled_label.cc?rcl=4456afbc261e3dd74d3e764a4de7a90aa9703a82&l=537
If you add a border to Label to paint its bounds visually, that should reveal if the Label itself is handling internal alignment incorrectly.

It's also possible that StyledLabel needs to set the alignment of the Labels that it creates.

I was confused this bug, it reports the body text alignment, not the text direction.

The default alignment of label was wrong. It should be always ALIGN_LEFT
no matter it is RTL or LTR. The default behavior is to align left in LTR
UI and right in RTL UI. 

Uploaded a cl to: crrev.com/c/1094328

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/51b82ab377fcaa288ac00464ebfc2398971109ca

commit 51b82ab377fcaa288ac00464ebfc2398971109ca
Author: wutao <wutao@chromium.org>
Date: Tue Jun 12 21:19:49 2018

StyledLabel: Fix default alignment in RTL

The default alignment of label was wrong. It should be always ALIGN_LEFT
no matter it is RTL or LTR. The default behavior is to align left in LTR
UI and right in RTL UI.

Bug:  850390 
Test: add new unittest: StyledLabelTest.*AlignmentInRTL*
Change-Id: I058afab144acd46e221f889c57207340ef5aa26e
Reviewed-on: https://chromium-review.googlesource.com/1094328
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566573}
[modify] https://crrev.com/51b82ab377fcaa288ac00464ebfc2398971109ca/ui/views/controls/styled_label.cc
[modify] https://crrev.com/51b82ab377fcaa288ac00464ebfc2398971109ca/ui/views/controls/styled_label.h
[modify] https://crrev.com/51b82ab377fcaa288ac00464ebfc2398971109ca/ui/views/controls/styled_label_unittest.cc

Request merge to M68.

M67 is already stable, maybe it is too late to merge to M67.

This bug requires manual review: M68 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: cmasso@(Android), kariahda@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Able to reproduce the issue on chrome version 67.0.3396.79
Verified the fix on Mac 10.12.6, Windows-10 & Ubuntu 14.04 on Chrome version #69.0.3457.0 as per the comment#0
Attaching screenshot for reference.
Observed "right-aligned body text"
Hence, the fix is working as expected.
Adding the verified label.

Thanks!

Deleted: 850390.png 329 KB

	850390.png 329 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d27fe8c4bc6ade806dc5fe495dc02c81598fad18

commit d27fe8c4bc6ade806dc5fe495dc02c81598fad18
Author: wutao <wutao@chromium.org>
Date: Wed Jun 13 19:54:08 2018

M68 merge: StyledLabel: Fix default alignment in RTL

The default alignment of label was wrong. It should be always ALIGN_LEFT
no matter it is RTL or LTR. The default behavior is to align left in LTR
UI and right in RTL UI.

TBR=msw@chromium.org

Bug:  850390 
Test: add new unittest: StyledLabelTest.*AlignmentInRTL*
Change-Id: I058afab144acd46e221f889c57207340ef5aa26e
Reviewed-on: https://chromium-review.googlesource.com/1094328
Commit-Queue: Tao Wu <wutao@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#566573}(cherry picked from commit 51b82ab377fcaa288ac00464ebfc2398971109ca)
Reviewed-on: https://chromium-review.googlesource.com/1099696
Reviewed-by: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/branch-heads/3440@{#342}
Cr-Branched-From: 010ddcfda246975d194964ccf20038ebbdec6084-refs/heads/master@{#561733}
[modify] https://crrev.com/d27fe8c4bc6ade806dc5fe495dc02c81598fad18/ui/views/controls/styled_label.cc
[modify] https://crrev.com/d27fe8c4bc6ade806dc5fe495dc02c81598fad18/ui/views/controls/styled_label.h
[modify] https://crrev.com/d27fe8c4bc6ade806dc5fe495dc02c81598fad18/ui/views/controls/styled_label_unittest.cc

Thank you viswa.karala@ and cmasso@.