Observed in 57.0.2987.19 on Linux without the experimental flags.

Seems like it may be a layout issue though.

Uses flexbox, unable to repro. Over to Christian for further triage.

Can reproduce on Windows canary.

This is odd, it's position: fixed with a specified right: 40px, but we position it much further in than 40px.

You are probably looking for a change made after 443052 (known good), but no later than 443061 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/205a9955bdcfbe37d8eecaad964e564a39fc4ef3..dc1892fc0639464d4418ccfaedfd1f95a5b947d0


This is the second bug I saw that blames this change:
513f1f0 [layoutng] Use the override width even when we're not a flex item by cbiesinger · 4 weeks ago

Seems odd that that would break something but I'm investigating.

Yeah definitely caused by that. I guess what happens is that the website sets position: fixed on something that previously was a flex item, and we never clear the override size.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3c12965b9c068f00290a4c4ecce1cc9d404ec20a

commit 3c12965b9c068f00290a4c4ecce1cc9d404ec20a
Author: cbiesinger <cbiesinger@chromium.org>
Date: Tue Feb 07 20:03:27 2017

[css-flexbox] Clear override sizes when we're no longer a flex item

When we change to being absolutely positioned, we need to clear the override
size so as to avoid being affected by it.

R=eae@chromium.org
BUG= 687747 , 688938 , 688253 

Review-Url: https://codereview.chromium.org/2684463002
Cr-Commit-Position: refs/heads/master@{#448709}

[add] https://crrev.com/3c12965b9c068f00290a4c4ecce1cc9d404ec20a/third_party/WebKit/LayoutTests/css3/flexbox/change-flexitem-into-abspos.html
[modify] https://crrev.com/3c12965b9c068f00290a4c4ecce1cc9d404ec20a/third_party/WebKit/Source/core/layout/LayoutBox.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/986dbbcbd724c5fb503b26ca44bec5b68dc3a88a

commit 986dbbcbd724c5fb503b26ca44bec5b68dc3a88a
Author: Christian Biesinger <cbiesinger@chromium.org>
Date: Wed Feb 08 21:14:43 2017

[css-flexbox] Clear override sizes when we're no longer a flex item

When we change to being absolutely positioned, we need to clear the override
size so as to avoid being affected by it.

R=eae@chromium.org
BUG= 687747 , 688938 , 688253 

Review-Url: https://codereview.chromium.org/2684463002
Cr-Commit-Position: refs/heads/master@{#448709}
(cherry picked from commit 3c12965b9c068f00290a4c4ecce1cc9d404ec20a)

Review-Url: https://codereview.chromium.org/2684073004 .
Cr-Commit-Position: refs/branch-heads/2987@{#395}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}

[add] https://crrev.com/986dbbcbd724c5fb503b26ca44bec5b68dc3a88a/third_party/WebKit/LayoutTests/css3/flexbox/change-flexitem-into-abspos.html
[modify] https://crrev.com/986dbbcbd724c5fb503b26ca44bec5b68dc3a88a/third_party/WebKit/Source/core/layout/LayoutBox.cpp

Verified on Mac os 10.12.2 , ubuntu 14.04 and windows 7 using chrome beta M57 #57.0.2987.54 and issue is fixed.

Steps followed :

1. Enabled the flags experimental web platform features and experimental javascript features  in chrome ://flags
2. Navigated to https://www.polymer-project.org/1.0/toolbox/app-layout and scrolled down  and didnt observe any overlap of text.

Attached screencast for reference.

Adding TE-Verified Labels.

Thanks!

Deleted: 687747.mp4 3.5 MB

	687747.mp4 3.5 MB View Download