Good build:55.0.2845.0
Bad build:55.0.2846.0

Per-revision Bisect result:
------------------------------
You are probably looking for a change made after 415557 (known good), but no later than 415592 (first known bad).
CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/3166b5e20f02c73995a1b4de28a4817678b1482d..29649b991045c05394dc42641068934b9d494e80

suspecting, https://chromium.googlesource.com/chromium/src/+/94405829a3ffa94bff257bb14650170f7422bad0
@ glebl, could you please check the issue.

Able to reproduce the issue on Canary #54.0.2894.0

Using flexbox and width: 70%. Is this a know issue or an intentional change Christian?

Unexpected -- the <fieldset> is not using display: flex.

I'm not really sure why this happens but it is not supposed to happen! Assigning to Gleb for now since this is his regression but I can take a look if you like.

layout tree in question below. maybe we are mishandling the floating <p>?
      LayoutFieldset {FIELDSET} at (0,0) size 220x94
        LayoutBlockFlow (anonymous) at (0,0) size 139.28x94
          LayoutBlockFlow {LEGEND} at (0,0) size 139.28x84
            LayoutText {#text} at (0,1) size 134x82
              text run at (0,1) width 134: "Get $5 off when you"
              text run at (0,22) width 121: "sign up for emails"
              text run at (0,43) width 113: "with savings and"
              text run at (0,64) width 29: "tips."
        LayoutBlockFlow (anonymous) at (139.28,0) size 80.72x94
          LayoutText {#text} at (0,0) size 0x0
          LayoutText {#text} at (0,0) size 0x0
          LayoutFlexibleBox (floating) {P} at (0,0) size 82.72x42 [border: (1px solid #CCCCCC)]
            LayoutTextControl {INPUT} at (1,1) size 20x40 [color=#000000] [bgcolor=#FFFFFF]
            LayoutButton {BUTTON} at (21,1) size 67x37 [color=#FFFFFF]
              LayoutBlockFlow (anonymous) at (0,0) size 67x37
                LayoutFlexibleBox {SPAN} at (0,0) size 67x37 [bgcolor=#F96302]
                  LayoutBlockFlow (anonymous) at (20,9.50) size 27x18
                    LayoutText {#text} at (0,-4) size 27x25
                      text run at (0,-4) width 27: "GO"

 Issue 658166  has been merged into this issue.

this happens because <legend> for that form is marked as "display: inline-block" and because of the change that was introduced here  http://crbug.com/481983  we try to place inline <legend> and float <p> elements inline.

Supporting display:inline-block <legend> is a violation of the HTML spec
https://html.spec.whatwg.org/multipage/rendering.html#rendered-legend
quote: "A fieldset element's rendered legend, if any, is expected to be rendered over the block-start border edge of the fieldset element as a block box (overriding any explicit 'display' value)"

I think the right fix for this bug would be to revert the change from  http://crbug.com/481983 , i.e. <legend> should always be displayed as a block box, overriding any explicit 'display' value. In this case we will be consistent with Firefox behavior https://bugzilla.mozilla.org/show_bug.cgi?id=653870.

fixed by reverting the patch from  http://crbug.com/481983 .

Verified this issue on Windows-10, Ubuntu 14.04 and Mac OS 10.12 using chrome latest Dev M56-56.0.2902.0 by following steps mentioned in the original comment. Observed 'Enter Email Address' text box is rendered properly as expected. Hence adding TE-Verified label.
	
glebl@ - Thanks for the fix! Could you please merge the same to latest M55 build, Since M55 is already in Beta and it will hit stable soon.

Thanks!

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	Screen Shot 2016-10-27 at 6.07.58 PM.png 213 KB View Download

glebl@ Gentle Ping! can we get any latest update regarding M55 merge?

added Merge-Request-55 label.

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5c2342bffcaaa4fe813ce95aa2546e54260211be

commit 5c2342bffcaaa4fe813ce95aa2546e54260211be
Author: Emil A Eklund <eae@chromium.org>
Date: Thu Nov 03 16:35:01 2016

Revert "Allow to set display "inline" on legend element"

This reverts commit 2383abb8b227d12ae53f2b163b57e02ff63dbf0b.

Reason: it violates the spec that says that fieldset's legend should be
displayed as a block box (overriding any explicit 'display' value).
Also it introduces an interop issue with Firefox
https://bugzilla.mozilla.org/show_bug.cgi?id=653870.

BUG= 656894 

Review-Url: https://codereview.chromium.org/2447843002
Cr-Commit-Position: refs/heads/master@{#427364}
(cherry picked from commit 07a1644e65e23598796babe8056dba9a986f3c33)

Review URL: https://codereview.chromium.org/2475003002 .

Cr-Commit-Position: refs/branch-heads/2883@{#434}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[add] https://crrev.com/5c2342bffcaaa4fe813ce95aa2546e54260211be/third_party/WebKit/LayoutTests/fast/forms/fieldset/inline-ignored-on-legend-expected.txt
[rename] https://crrev.com/5c2342bffcaaa4fe813ce95aa2546e54260211be/third_party/WebKit/LayoutTests/fast/forms/fieldset/inline-ignored-on-legend.html
[delete] https://crrev.com/679d6fbb849b2239be8deaf6dff100150b19c71e/third_party/WebKit/LayoutTests/fast/forms/fieldset/inline-legend-expected.txt
[modify] https://crrev.com/5c2342bffcaaa4fe813ce95aa2546e54260211be/third_party/WebKit/Source/core/css/resolver/StyleAdjuster.cpp
[modify] https://crrev.com/5c2342bffcaaa4fe813ce95aa2546e54260211be/third_party/WebKit/Source/core/layout/LayoutFieldset.cpp

Verified the issue on Windows-10, Ubuntu 14.04 and Mac 10.11.16 using chrome beta build #55.0.2883.44 by following steps as per comment #0. 

Observed 'Enter Email Address' text box is rendered properly as expected.

Attaching screen cast for reference

The fix is working as expected for M-55. Hence, adding the verified labels.

Thanks...!!

Deleted: 656894.ogv 9.1 MB

	656894.ogv 9.1 MB View Download