As per the details in the bug, this looks like an android issue. Tagging accordingly.

This issue is not specific to amazon.com
gmail.com (post login) also has an absolutely broken UI in v54+ (to the point of being unusable) when using 200% zoom and it looks perfectly fine in v53 and earlier

(Sorry for the delete above - the comment was unclear in regards to this only happening with active zoom. Gmail of course looks fine when no zoom setting is set)

kravula@ - can you try to repro?

Tested with Nexus7/LMY47T and able to repro on M54 build

Bisect info
Good Build-54.0.2840.33
Bad Build -54.0.2840.34
CL range -https://chromium.googlesource.com/chromium/src/+log/54.0.2840.33..54.0.2840.34?pretty=fuller&n=10000

Suspect CL -https://chromium.googlesource.com/chromium/src/+/d25ac697753f02ac5c923d65402d75b4211cab28
Review-Url: https://codereview.chromium.org/2340553003

Similar issue -https://bugs.chromium.org/p/chromium/issues/detail?id=648928

I just reverted d25ac697753f02ac5c923d65402d75b4211cab28 in a v54 workspace and it DOES fix the issue.
Great find kravula@! :)

Please note that this isn't just specific to Chromium's font size setting. (Which used to be separate from Android platform font size)
Changing Android's font size setting will now also cause this issue.
--> This might potentially impact more users than initially assumed.

This will indeed be fixed by 645717.

I am still a little puzzled why the change to honor text-size-adjust would cause this breakage; we should have honored the accessibility font scale factor before and after the change. I will investigate this independently of Aelias's work in 645717.

Great, thanks pdr! :)
Do you by any chance know if 645717 is planned to go into v55?

645717 is not currently planned for v55.

Good to know, thanks!

Is there any chance this might get re-prioritized? (Or worst case putting a revert of d25ac697 into v55 as a stopgap?)
I don't know the exact numbers of Android users that have a large font size, but even if we are only talking 1%, that would be tens of millions of users who can't use Gmail, Google Flights, or thousands of other websites. :(

This is indeed a bug. Patch up to fix it: https://codereview.chromium.org/2514733005

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/394de7b0baa6b0136b6acfd15486de6a98e19152

commit 394de7b0baa6b0136b6acfd15486de6a98e19152
Author: pdr <pdr@chromium.org>
Date: Tue Nov 22 02:54:40 2016

Only apply accessibility font scale factor when autosizing inflates

The accessibility font scale factor is currently applied to all text
that the text autosizer would inflate (this is changing in
crbug.com/645717). crrev.com/1229b1414d64c314666d2fb3bf47706f2b5e947b
introduced a bug where text that would not be inflated would become
inflated if text-size-adjust: none was applied.

This patch only applies the accessibility font scale factor if the
text autosizer would have inflated the text already. A new test,
AccessibilityFontScaleFactorWithTextSizeAdjustNone, has been added.
Other tests in TestAutosizerTest.cpp have been reformatted to 80cols.

BUG= 666378 

Review-Url: https://codereview.chromium.org/2514733005
Cr-Commit-Position: refs/heads/master@{#433757}

[modify] https://crrev.com/394de7b0baa6b0136b6acfd15486de6a98e19152/third_party/WebKit/Source/core/layout/TextAutosizer.cpp
[modify] https://crrev.com/394de7b0baa6b0136b6acfd15486de6a98e19152/third_party/WebKit/Source/core/layout/TextAutosizerTest.cpp

TPMs, this regressed in M54 and affects users with accessibility font settings when visiting some sites that have text-size-adjust: none, including Amazon.com. I'm requesting a merge because it affects at least one large site and the fix is straightforward (3 lines).

Your change meets the bar and is auto-approved for M55 (branch: 2883)

Merged in https://codereview.chromium.org/2527483002 / https://chromium.googlesource.com/chromium/src/+/5a3e6f1238c826cd4dd99c541d359471ffe181e8

Issue is fixed on Latest M55 Beta Build, Issue is reproducible on M56 Dev. Do we need to merge required for M56.

Can we get this merged in M56 too?

@TPMs, this has already been merged into M55. It was only an oversight that we didn't get M56 too.

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e185926ca8f2014314df6b7a8c345607323d4580

commit e185926ca8f2014314df6b7a8c345607323d4580
Author: pdr@chromium.org <pdr@chromium.org>
Date: Wed Nov 30 21:10:53 2016

Only apply accessibility font scale factor when autosizing inflates

The accessibility font scale factor is currently applied to all text
that the text autosizer would inflate (this is changing in
crbug.com/645717). crrev.com/1229b1414d64c314666d2fb3bf47706f2b5e947b
introduced a bug where text that would not be inflated would become
inflated if text-size-adjust: none was applied.

This patch only applies the accessibility font scale factor if the
text autosizer would have inflated the text already. A new test,
AccessibilityFontScaleFactorWithTextSizeAdjustNone, has been added.
Other tests in TestAutosizerTest.cpp have been reformatted to 80cols.

BUG= 666378 

Review-Url: https://codereview.chromium.org/2514733005
Cr-Commit-Position: refs/heads/master@{#433757}
(cherry picked from commit 394de7b0baa6b0136b6acfd15486de6a98e19152)

Review URL: https://codereview.chromium.org/2544633002 .

Cr-Commit-Position: refs/branch-heads/2924@{#208}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[modify] https://crrev.com/e185926ca8f2014314df6b7a8c345607323d4580/third_party/WebKit/Source/core/layout/TextAutosizer.cpp
[modify] https://crrev.com/e185926ca8f2014314df6b7a8c345607323d4580/third_party/WebKit/Source/core/layout/TextAutosizerTest.cpp

Verified in 55.0.2883.71 with Nexus7