Able to reproduce the issue on Windows 10 and mac 10.11.6 using chrome reported version #54.0.2840.99 and latest canary #57.0.2931.0. Unable to reproduce on Ubuntu 14.04.

Bisect Information:
=====================
Good build: 52.0.2734.0 Revision(393126)
Bad Build : 52.0.2735.0 Revision(393409) 

Change Log URL: 
https://chromium.googlesource.com/chromium/src/+log/b0023a6712afe431a21e209bf6066c2413733e19..ad66862296c227c1b74a15f96632a67d941b6643

From the above change log suspecting below change

Review url: https://codereview.chromium.org/1966703002

kojii@ - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks...!!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f2ba82966d78cccb307a6046606a616e27c1f0df

commit f2ba82966d78cccb307a6046606a616e27c1f0df
Author: kojii <kojii@chromium.org>
Date: Fri Dec 02 10:03:59 2016

Fix break-all/word-break are applied to inline elements

This patch improves when properties that can break lines in the middle
of a word (word-break: break-all and break-word) are applied to inline
elements.

When no characters can fit but there is a break opportunity in previous
runs, the line should break at the opportunity.

Also this fix revealed that we have tests of element boundaries relying
on parent's style, and they pass only under certain conditions. This
was fixed to refer to the parent's style, as recently clarified in CSS
Text[1].

[1] https://github.com/w3c/csswg-drafts/issues/189

BUG= 668399 

Review-Url: https://codereview.chromium.org/2532393006
Cr-Commit-Position: refs/heads/master@{#435899}

[add] https://crrev.com/f2ba82966d78cccb307a6046606a616e27c1f0df/third_party/WebKit/LayoutTests/fast/css3-text/css3-word-break/word-break-break-all-in-span-expected.html
[add] https://crrev.com/f2ba82966d78cccb307a6046606a616e27c1f0df/third_party/WebKit/LayoutTests/fast/css3-text/css3-word-break/word-break-break-all-in-span.html
[modify] https://crrev.com/f2ba82966d78cccb307a6046606a616e27c1f0df/third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h

Thank you for reporting this issue. The fix is available in today's Canary, it'd be greatly appreciated if you could verify your pages.

Also, I took the hyphenation issue you mentioned in your blog to CSS WG:
https://github.com/w3c/csswg-drafts/issues/785
It'd be also helpful if you could follow the discussion.

Your change meets the bar and is auto-approved for M56 (branch: 2924)

Looks great. Thank you.

Deleted: cap-20161206-133956.png 12.3 KB

	cap-20161206-133956.png 12.3 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/58e8ebffee4354ed11d2308a6dca6ea7cca6ace3

commit 58e8ebffee4354ed11d2308a6dca6ea7cca6ace3
Author: Koji Ishii <kojii@chromium.org>
Date: Tue Dec 06 12:42:57 2016

Merge 2924: Fix break-all/word-break are applied to inline elements

This patch improves when properties that can break lines in the middle
of a word (word-break: break-all and break-word) are applied to inline
elements.

When no characters can fit but there is a break opportunity in previous
runs, the line should break at the opportunity.

Also this fix revealed that we have tests of element boundaries relying
on parent's style, and they pass only under certain conditions. This
was fixed to refer to the parent's style, as recently clarified in CSS
Text[1].

[1] https://github.com/w3c/csswg-drafts/issues/189

BUG= 668399 

Review-Url: https://codereview.chromium.org/2532393006
Cr-Commit-Position: refs/heads/master@{#435899}
(cherry picked from commit f2ba82966d78cccb307a6046606a616e27c1f0df)

Review URL: https://codereview.chromium.org/2555493004 .

Cr-Commit-Position: refs/branch-heads/2924@{#355}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[add] https://crrev.com/58e8ebffee4354ed11d2308a6dca6ea7cca6ace3/third_party/WebKit/LayoutTests/fast/css3-text/css3-word-break/word-break-break-all-in-span-expected.html
[add] https://crrev.com/58e8ebffee4354ed11d2308a6dca6ea7cca6ace3/third_party/WebKit/LayoutTests/fast/css3-text/css3-word-break/word-break-break-all-in-span.html
[modify] https://crrev.com/58e8ebffee4354ed11d2308a6dca6ea7cca6ace3/third_party/WebKit/Source/core/layout/line/BreakingContextInlineHeaders.h

As per comment #7. Thank you for your quick verification.