[Affected versions]: - Firefox 61.0b3 [Affected platforms]: - Windows 7 x 64 - Mac OS X 10.13 - Ubuntu 14.04 x64. [Steps to reproduce]: 1. Open Firefox. 2. Open the Inspector by pressing F12. 3. Click on the Meatball Menu and click on settings menu item. 4. From Advanced settings section enable "Enable browser chrome and add-on debugging toolboxes" and "Enable remote debugging", then go to Tools -> Web Developer -> Browser Toolbox to display the Developer Tools window. 5. Click on the Meatball Menu/Settings then from Default Developer Tools section check Performance item. 6. Close the Developer Tools window then reopen it. [Expected result]: After reopen the Developer Tools window the Performance tab should be saved, displayed in menu, verified in Meatball Menu/Settings Default Developer Tools section the Performance item should be checked. [Actual result]: The Performance tab is not displayed in Developer Tools window menu and is unchecked in Meatball/Settings Default Developer Tools section.

Brian, do you think this could somehow be related to bug 1457278?

(In reply to Patrick Brosset <:pbro> from comment #1) > Brian, do you think this could somehow be related to bug 1457278? Yes, the pref gets reset to false at Browser Toolbox startup so it will never be included in the default set. We could probably fix this with a second pref to track whether the user has added perf (or something like that). But, given the discussion / justification for removing it from the default set in that bug I don't see a benefit to doing that. Devs should instead use https://perf-html.io/ to get better and more shareable profiles. I wonder if we should instead hide the checkbox for the Performance tool in the Browser Toolbox options to prevent confusion. Timea, do you have a use-case for using the Performance tool from the Browser Toolbox?

In my opinion could be a solution for this issue, to hide the checkbox for the Performance tool in the Browser Toolbox option, like Shader Editor, Canvas and Web Audio tools. I found this issue when I tested "Improved Developer Tools tab bar navigation" feature, there is a test about saving and loading the tabs order preference.

If there is something about this that blocks the re-ordering feature, it should probably block that bug.

Moving this inactive P2 to the backlog (P3)