Tested in chrome # 61.0.3163.31,Canary #62.0.3180.0 on Mac 10.12.6 and able to reproduce the issue in Beta and not in Canary.Please find the screen shots for your reference.

@islam: Could you please let me know if i have missed anything and if possible,Please create new profile without extensions and apps.Re-check once in latest Canary(62.0.3180.0)and let us know the observations and expected behaviour of the issue which would help us to triage the issue further.

Thanks in Advance.

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@rbasuvula, I think my bug report wasn't super clear, the expected output is to have "copying <random number>" and then when you paste "yoyoma: <random number>". So in the screenshot you added of canary, that looks to reproduce the bug

For reference I'm adding a screenshot of chrome 60 expected output.

I just retested in 60, Beta (61.0.3163.31), and Canary (62.0.3180.0) -- I can reproduce in both beta and canary.

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Also note that you don't need to select the next in the lower right quadrant, I just want to make sure it had focus.

Thank you for providing more feedback. Adding requester "rbasuvula@chromium.org" to the cc list and removing "Needs-Feedback" label.

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

Thanks for the update!
Tested in chrome Beta #61.0.3163.31 and canary #62.0.3181.0 on Mac 10.12.6,Ubuntu 14.04 & Win 10.0 able to reproduce the issue.
Below are the Bisect Details:

Bisect Info:
------------
Good Build: 61.0.3142.0(Revision - 482491)
Bad Build: 61.0.3143.0(Revision - 482834)

You are probably looking for a change made after 482625 (known good), but no later than 482626 (first known bad).

CHANGELOG URL:
https://chromium.googlesource.com/chromium/src/+log/997b71924f38eb831ba87cf97a07371100715268..56f9a641544d2cafa37142545bb39254f7bd98b3

From the CL above, assigning the issue to the concern owner

@avi: Could you please look into the issue, pardon me if it has nothing to do with your changes and if possible please assign it to concern owner.

Review-Url:  https://codereview.chromium.org/2957923002

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8b750849271adebe4dc164d1101ccaaa3790f922

commit 8b750849271adebe4dc164d1101ccaaa3790f922
Author: Avi Drissman <avi@chromium.org>
Date: Thu Aug 10 21:18:26 2017

Revert "Don't count browser shortcut events as being user gestures."

This reverts commit 56f9a641544d2cafa37142545bb39254f7bd98b3.

The lack of a user gesture for browser shortcut events causes web
compatibility issues. This needs a better-engineered approach.

BUG=709765,  749005 ,  753612 ,  741612 
TEST=as in bugs

Change-Id: I2faee9623597561297e01756b4bdf6f56c049eeb
Reviewed-on: https://chromium-review.googlesource.com/610829
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#493549}
[modify] https://crrev.com/8b750849271adebe4dc164d1101ccaaa3790f922/third_party/WebKit/Source/core/input/KeyboardEventManager.cpp

Calling this fixed; asking for a merge to 61 on a different bug.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0234225c87bd459b2039d642921e9a7ad502eb89

commit 0234225c87bd459b2039d642921e9a7ad502eb89
Author: Avi Drissman <avi@chromium.org>
Date: Fri Aug 11 17:35:51 2017

Revert "Don't count browser shortcut events as being user gestures."

This reverts commit 56f9a641544d2cafa37142545bb39254f7bd98b3.

The lack of a user gesture for browser shortcut events causes web
compatibility issues. This needs a better-engineered approach.

BUG=709765,  749005 ,  753612 ,  741612 
TEST=as in bugs
TBR=avi@chromium.org

Change-Id: I2faee9623597561297e01756b4bdf6f56c049eeb
Reviewed-on: https://chromium-review.googlesource.com/610829
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#493549}(cherry picked from commit 8b750849271adebe4dc164d1101ccaaa3790f922)
Reviewed-on: https://chromium-review.googlesource.com/611668
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#490}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/0234225c87bd459b2039d642921e9a7ad502eb89/third_party/WebKit/Source/core/input/KeyboardEventManager.cpp

Tested the issue on Windows-7, Ubuntu 14.04 and Mac OS 10.12 using chrome latest Beta M61-61.0.3163.49 by following steps mentioned in the original comment. Observed that issue is working fine in mac but able to reproduce in Windows and Linux.Please find the screen shot for reference.

@avi: Could you please check the attached screen shot and let me know if i have missed anything and if possible,Please provide the windows and Linux behaviour of the issue which would help us to verify the issue further.

Thanks in Advance.

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That test page was Mac-only.

If you alter the test page's onKeyDown event to say:

function onKeyDown(event) {
  console.log('keydown', event)
  event.preventDefault()
  event.stopPropagation()
  if (event.key == 'c' && (event.metaKey || event.ctrlKey)) {
    copy()  
  }
}

you will see that it works on Windows/Linux now too.

Note sure this is correct behavior but here is what I am seeing when I updated the test page with comment#13 

Steps to reproduce the problem:
1. Open this jsfiddle: https://jsfiddle.net/a469yLz5/(changed function onKeyDown(event) as per comment#13)
2. Open dev tools console
3. Click in the frame on the lower right
4. Press "cmd+c"


Observed behavior on JS console on Windows and Linux:
keydown KeyboardEvent {isTrusted: true, key: "Control", code: "ControlLeft", location: 1, ctrlKey: true, …}
(index):62 keydown KeyboardEvent {isTrusted: true, key: "Control", code: "ControlLeft", location: 1, ctrlKey: true, …}
(index):62 keydown KeyboardEvent {isTrusted: true, key: "c", code: "KeyC", location: 0, ctrlKey: true, …}
(index):56 called copy
(index):50 copying 0.7327771430398045

@pbomm that is the correct behavior