Using the per-revision bisect providing the bisect results,
Good build: 56.0.2918.0 (Revision: 431795).
Bad build: 56.0.2920.0 (Revision: 432057).

You are probably looking for a change made after 432052 (known good), but no later than 432053 (first known bad).

CHANGE-LOG URL:
---------------------------------------
https://chromium.googlesource.com/chromium/src/+log/653aaed16ec270dcb3c4da44a5adabb501228bc3..15099fe2bbea4d7a205c0ef6220d23cfc6a802e2


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

@ mlamouri : 
------------------
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/2477203002

Note : Able to reproduce the issue in Mac10.12.2,Win10.0 & ubuntu 14.04.

Thank you for the report. I will look into this.

Able to reproduce the issue on windows using chrome version 57.0.2976.0.

mlamouri@ Could you please update on this issue.

Thanks,

Thanks for the ping. I've uploaded a fix.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e8a0940aae4094d975ccc14f7398154b80e8b42a

commit e8a0940aae4094d975ccc14f7398154b80e8b42a
Author: mlamouri <mlamouri@chromium.org>
Date: Wed Jan 11 10:44:28 2017

Media Controls: invalidate volume slider when value changes.

Otherwise, the painting will not take into consideration the new
value.

BUG= 677903 

Review-Url: https://codereview.chromium.org/2616343004
Cr-Commit-Position: refs/heads/master@{#442864}

[modify] https://crrev.com/e8a0940aae4094d975ccc14f7398154b80e8b42a/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

Your change meets the bar and is auto-approved for M56. Please go ahead and merge the CL manually. Please contact milestone owner if you have questions.
Owners: amineer@(clank), cmasso@(bling), gkihumba@(cros), bustamante@(desktop)

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

Verified the issue on windows 10, Ubuntu 14.04 and Mac 10.12.2 using chrome version #57.0.2979.0 as per the comment #0.

Observed that the fix is working as expected.

Attaching screencast for reference

Hence, adding the verified labels.

Thanks...!!

Deleted: 677903.ogv 2.4 MB

	677903.ogv 2.4 MB View Download

Your change has been approved for M56 , please merge ASAP. 

Sorry for the delay, I was trying to figure out the branch number given that the new auto-approval message no longer shows it

It's all sorted out and the merge should be in soon.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/618b6b013173b4a37e450039740d98c2281ad3b4

commit 618b6b013173b4a37e450039740d98c2281ad3b4
Author: Mounir Lamouri <mlamouri@chromium.org>
Date: Mon Jan 16 11:33:41 2017

Media Controls: invalidate volume slider when value changes.

Otherwise, the painting will not take into consideration the new
value.

BUG= 677903 

Review-Url: https://codereview.chromium.org/2616343004
Cr-Commit-Position: refs/heads/master@{#442864}
(cherry picked from commit e8a0940aae4094d975ccc14f7398154b80e8b42a)

Review-Url: https://codereview.chromium.org/2638623003 .
Cr-Commit-Position: refs/branch-heads/2924@{#771}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[modify] https://crrev.com/618b6b013173b4a37e450039740d98c2281ad3b4/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp

Tested the issue on win10, mac 10.12.2 and Linux 14.04 chrome version 56.0.2924.67 - Blue highlight not seen on input bar after clicking volume icon.

Fix works as expected

Deleted: Recording #19.mp4 865 KB

	Recording #19.mp4 865 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4d9872c0015abd0cac4cbaeeb36585109f1b13e8

commit 4d9872c0015abd0cac4cbaeeb36585109f1b13e8
Author: sabbakumov <sabbakumov@yandex-team.ru>
Date: Thu Apr 06 01:30:17 2017

Redraw media volume slider when it is moving

Steps to reproduce:
1. Launch Chromium http://www.quirksmode.org/html5/tests/video.html
2. Try to change the video volume by dragging the volume slider while
holding the mouse key.
3. The volume slider isn't updated. It updates only when the mouse
button is released.

BUG= 677903 

Review-Url: https://codereview.chromium.org/2783593002
Cr-Commit-Position: refs/heads/master@{#462310}

[modify] https://crrev.com/4d9872c0015abd0cac4cbaeeb36585109f1b13e8/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
[modify] https://crrev.com/4d9872c0015abd0cac4cbaeeb36585109f1b13e8/third_party/WebKit/Source/core/html/shadow/MediaControlsTest.cpp
[modify] https://crrev.com/4d9872c0015abd0cac4cbaeeb36585109f1b13e8/third_party/WebKit/Source/core/layout/LayoutObject.h

Thanks sabbakumov for the follow-up :)