The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e

commit 94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e
Author: alph <alph@chromium.org>
Date: Sat Oct 08 02:00:01 2016

DevTools: CPU throttling should disable when DevTools are closed.

BUG= 654138 

Review-Url: https://codereview.chromium.org/2399883005
Cr-Commit-Position: refs/heads/master@{#424042}

[modify] https://crrev.com/94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp

[Automated comment] Less than 2 weeks to go before stable on M54, manual review required.

Your change meets the bar and is auto-approved for M55 (branch: 2883)

Your change meets the bar and is auto-approved for M55 (branch: 2883)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4b18f021b28b4505f72f9ee7699e5909f0e9701b

commit 4b18f021b28b4505f72f9ee7699e5909f0e9701b
Author: Alexei Filippov <alph@chromium.org>
Date: Mon Oct 10 18:34:54 2016

DevTools: CPU throttling should disable when DevTools are closed.

BUG= 654138 

Review-Url: https://codereview.chromium.org/2399883005
Cr-Commit-Position: refs/heads/master@{#424042}
(cherry picked from commit 94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e)

Review URL: https://codereview.chromium.org/2404923003 .

Cr-Commit-Position: refs/branch-heads/2883@{#15}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/4b18f021b28b4505f72f9ee7699e5909f0e9701b/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp

This change meets the bar and is approved for M54, please merge than change by 5pm today to make it in time for tonight's stable cut.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/778c47b7cbf6424faa66e77efc451d39bce02918

commit 778c47b7cbf6424faa66e77efc451d39bce02918
Author: Alexei Filippov <alph@chromium.org>
Date: Mon Oct 10 20:49:42 2016

DevTools: CPU throttling should disable when DevTools are closed.

BUG= 654138 

Review-Url: https://codereview.chromium.org/2399883005
Cr-Commit-Position: refs/heads/master@{#424042}
(cherry picked from commit 94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e)

Review URL: https://codereview.chromium.org/2407973002 .

Cr-Commit-Position: refs/branch-heads/2840@{#706}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/778c47b7cbf6424faa66e77efc451d39bce02918/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp

Steps to verify:
1. Open a page, preferable with an animation, e.g. http://codepen.io/eltonkamami/full/ECrKd/
2. Open DevTools Timeline panel
3. Set CPU throttling to 5x slowdown.
4. Notice the animation gets janky.
5. Close DevTools, the animation should be smooth again.

Verified the fix on Windows 7, 10, Mac OSX 10.11.6 and Linux(ubuntu 14.04Lts) with Chrome version 55.0.2883.9 and followed steps from comment#11 and there are no jankyness once Devtools is closed(Animation was smooth again).

Verified the issue on windows 7, Linux Ubuntu 14.04 and Mac 10.11.6 using chrome version 54.0.2840.59.Observed animation was smooth when devtools was closed.
Please find the attached screen cast for the same.

Adding TE-Verified labels.

Deleted: 654138.mp4 21.1 MB

654138.mp4 21.1 MB Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4b18f021b28b4505f72f9ee7699e5909f0e9701b

commit 4b18f021b28b4505f72f9ee7699e5909f0e9701b
Author: Alexei Filippov <alph@chromium.org>
Date: Mon Oct 10 18:34:54 2016

DevTools: CPU throttling should disable when DevTools are closed.

BUG= 654138 

Review-Url: https://codereview.chromium.org/2399883005
Cr-Commit-Position: refs/heads/master@{#424042}
(cherry picked from commit 94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e)

Review URL: https://codereview.chromium.org/2404923003 .

Cr-Commit-Position: refs/branch-heads/2883@{#15}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/4b18f021b28b4505f72f9ee7699e5909f0e9701b/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/778c47b7cbf6424faa66e77efc451d39bce02918

commit 778c47b7cbf6424faa66e77efc451d39bce02918
Author: Alexei Filippov <alph@chromium.org>
Date: Mon Oct 10 20:49:42 2016

DevTools: CPU throttling should disable when DevTools are closed.

BUG= 654138 

Review-Url: https://codereview.chromium.org/2399883005
Cr-Commit-Position: refs/heads/master@{#424042}
(cherry picked from commit 94eb2d6a00a578b21a22f5c8cc9e5661d29b2a9e)

Review URL: https://codereview.chromium.org/2407973002 .

Cr-Commit-Position: refs/branch-heads/2840@{#706}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/778c47b7cbf6424faa66e77efc451d39bce02918/third_party/WebKit/Source/web/InspectorEmulationAgent.cpp