Note: columns do resize when the number of columns decreases, just not when it increases.

Note: Changing the width is an invisible (yet disgusting) work-around if you add and remove ~1/64th of a pixel from the scroller's width.

@joolschadwick -- Thank You for the report.
Could you please provide us a screen shot or screen cast explaining the exact issue which would help us triaging the issue further.
Thanks in Advance.

See the attached gif. It shows the above linked jsfiddle side by side in chrome (left) firefox (right). Firefox is showing the correct behaviour (the same as Safari and IE). 

The jsfiddle is a flex-box (using column wrap) list inside a scrollable container. Using the bottoms at the button of the jsfiddle you can make the scrollable container smaller so that a second column gets introduced. All other browsers then resize the columns. 

However Chrome doesn't resize the columns when you only change the container *height*. It only resizes them when you change the container *width*. The "Tickle my width" button adds and removes a pixel from the container, therefore triggering the resize that Chrome should have done already.

Deleted: flex colum resize.gif 393 KB

	flex colum resize.gif 393 KB View Download

Using the buttons at the bottom*

I think this might be related to the following case:
https://bugs.chromium.org/p/chromium/issues/detail?id=607262
The steps and symptoms are bit different, but it can worked around using the same hack of changing the width.

Thank you for providing more feedback. Adding requester "msrchandra@chromium.org" for another review and adding "Needs-Review" label for tracking.

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

@joolschadwick -- Thank You for the quick response.
Able to reproduce the issue on Latest Stable# 50.0.2661.94 on Windows, Mac and Linux. 
This is a regression issue broken in M34, below is the CL:

CHANGELOG URL:
  https://chromium.googlesource.com/chromium/src/+log/4a55203bc97b03c28416bd640de0272d5a17e44f..ac7797414b1f49a0ce9bed37c43b6f6eec04f364

Thank You.

There's a blink roll in there:

164685:164830 = 24f38e983c25faa340063dd8fa43cf710ac2b29d..8f80c85cd14c4ede4a6c0690b0879ba14660d2fc


https://chromium.googlesource.com/chromium/src/+log/24f38e983c25faa340063dd8fa43cf710ac2b29d..8f80c85cd14c4ede4a6c0690b0879ba14660d2fc

so many :(

Tentatively https://chromium.googlesource.com/chromium/src/+/749d2c98c9cec9b252c612b8f4e0a95e706a2d80

Moving this nonessential bug to the next milestone.

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

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c83fe889c7045ad03b0b0a2e8d4fdcf1330d29ce

commit c83fe889c7045ad03b0b0a2e8d4fdcf1330d29ce
Author: cbiesinger <cbiesinger@chromium.org>
Date: Wed Jun 29 21:06:44 2016

[css-flexbox] childIntrinsicWidth needs to actually return the intrinsic width

This function is used to determine the cross size of a flex
line. If we just use .width() then it is potentially affected
by a previous layout where we already stretched the child.
To avoid that, switch to maxPreferredLogicalWidth() --
we already use that in childIntrinsicHeight, and we also
use intrinsicContentLogicalHeight() for the height case.

However, if we have a non-auto width, we can't necessarily
just call maxPreferredLogicalWidth; the preferred width
may not have percentages correctly resolved, for example.

TEST=css3/flexbox/wrapping-column-dynamic-changes.html
BUG= 607856 , 607262 

Review-Url: https://codereview.chromium.org/2104123002
Cr-Commit-Position: refs/heads/master@{#402932}

[add] https://crrev.com/c83fe889c7045ad03b0b0a2e8d4fdcf1330d29ce/third_party/WebKit/LayoutTests/css3/flexbox/wrapping-column-dynamic-changes.html
[modify] https://crrev.com/c83fe889c7045ad03b0b0a2e8d4fdcf1330d29ce/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp

Verified the issue on Latest Dev# 53.0.2785.8 on Windows, Mac and Linux and is working as intended.
Hence addint TE-Verified Labels.
Thank You.