Thanks arv. I can reproduce on CrOS 53.0.2785.55 (Official Build) beta (64-bit).

This is probably a regression, would be good if someone could bisect this.

Thanks for the report.

providing manual bisect, unable to get the version info from Omahaproxy (error msg: The requested version information could not be found at this time. An exception has been logged for the maintainer.)
CL:
https://chromium.googlesource.com/chromium/src/+log/36.0.1975.0..36.0.1976.0?pretty=fuller&n=10000

Good Build: 36.0.1975.0
Bad Build: 36.0.1976.0

Able to reproduce the issue on Win7, Mac OS X 10.11.6, Ubuntu 14.04 using Chrome Stable 52.0.2743.116, Beta 53.0.2785.70, Dev 54.0.2832.2 and Canary #54.0.2835.0

yosin@, could you please check and let me know if any more information is required from my end.

I am checking this one.

yosin@  I checked this behaviour, and found the place from where this behaviour is happening, and i can see that this behaviour is particularly done for Label.
  "If selection is there and is single click i.e. text is
  selected by dragging over label text, then return.
  Click count >=2, meaning double click or triple click,
  should pass click event to control element.
  Only in case of drag, *neither* we pass the click event,
  *nor* we focus the control element."

So this looks that the current behaviour has been restricted in code for this issue. Let me know your views please. 

I can still reproduce this on Linux 57.0.2987.133 (Official Build) (64-bit).

We should fix this regression.

In review: http://crrev.com/2833313003

tanvir.rizvi@ is working. yosin@ is a virtual owner. 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5db23fe6d7151affeaf8b84ac2b16cf1603c456d

commit 5db23fe6d7151affeaf8b84ac2b16cf1603c456d
Author: tanvir.rizvi <tanvir.rizvi@samsung.com>
Date: Fri May 19 10:46:36 2017

Pass clickEvent to controlElement inside label if target node can't start selection.

On selection of any text in the HTML content, if any of the image
in a label is clicked, radio input is not selected.

This CL fixes this issue, the click events were not getting passed
to the control elements, as for few elements like image, update
selection is not done on single click as |CanMouseDownStartSelect()|
returns false. So this CL checks whether a selection could be done
on an element inside label.

BUG= 637516 
TEST=run_layout_test fast/forms/label/label-selection-by-textSelection-and-click.html

Review-Url: https://codereview.chromium.org/2833313003
Cr-Commit-Position: refs/heads/master@{#473151}

[add] https://crrev.com/5db23fe6d7151affeaf8b84ac2b16cf1603c456d/third_party/WebKit/LayoutTests/fast/forms/label/label-selection-by-textSelection-and-click.html
[modify] https://crrev.com/5db23fe6d7151affeaf8b84ac2b16cf1603c456d/third_party/WebKit/Source/core/html/HTMLLabelElement.cpp

 Issue 614328  has been merged into this issue.