The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/edb3fe56e289a8a7bad2473f3f83cc6acc14ec9b

commit edb3fe56e289a8a7bad2473f3f83cc6acc14ec9b
Author: Saman Sami <samans@chromium.org>
Date: Thu May 24 20:12:49 2018

Add ARGB to VideoCapturePixelFormat enum

http://crrev.com/1cecc36 broke DevTools eyedropper tool.

Bug:  846379 
Change-Id: I812b66c32192166b3c34582bf6b63407709ba784
Reviewed-on: https://chromium-review.googlesource.com/1072034
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561600}
[modify] https://crrev.com/edb3fe56e289a8a7bad2473f3f83cc6acc14ec9b/media/capture/mojom/video_capture_types.mojom
[modify] https://crrev.com/edb3fe56e289a8a7bad2473f3f83cc6acc14ec9b/media/capture/mojom/video_capture_types_mojom_traits.cc

Able to reproduce this issue on build without fix, hence verifying the fix on latest canary 68.0.3440.0 using Windows 10 and Mac 10.13.3 and 68.0.3440.2 using Ubuntu 14.04.

Now observing eye dropper on opening color picker ind devtools. Attaching screencast for reference.

As fix is working as intended adding Verified labels.

Thanks!

Deleted: 846379.mp4 833 KB

	846379.mp4 833 KB View Download

Thanks for the fix! 

 Issue 839742  has been merged into this issue.

I just noticed while trying this on the latest Mac Beta 68.0.3440.68 that this seems to be broken again. Not sure how critical this is, but this version is going to be promoted to stable very soon.

Adding release-block-stable label to get attention so that we can make an informed decision on whether or not stable release should be blocked by this.

In the meantime I am going to do a bisect to find out when and why it broke again.

Sorry, I think this was a false alarm. The issue I have seen only happens when the dev tools window is undocked, see  Bug 838099 .