[Affected versions]: - Firefox 52.0a2 (2016-12-22), Firefox 53.0a1 (2016-12-22) [Affected platforms]: - Ubuntu 16.04x64, Windows 8.1x86, Mac 10.12.1 [Steps to reproduce]: Prerequisites: Make sure that devtools.responsive.html.enabled pref is set to true. 1. Launch Firefox. 2. Enable RDM. 3. Open the list of devices and click on the 'Edit list...' button in order to open the modal. 4. Use the up/down arrow keys or the tab key. [Expected result]: - The focus is set on the modal and all the actions are performed on it. [Actual result]: - The focus is on the viewport and actions can be taken on it. [Regression range]: - This is not a regression since is reproducible ever since the modal was implemented (20.04.2016).

(In reply to Mihai Boldan, QA [:mboldan] from comment #0) > [Regression range]: > - This is not a regression since is reproducible ever since the modal was > implemented (20.04.2016). This is not entirely accurate. Here is the pushlog in order to see when the modal was implemented: https://hg.mozilla.org/integration/fx-team/pushloghtml?fromchange=c1a9497a212d54fda334e9174aac33926196df8e&tochange=be1fd1c7e43f3969243b8c768d5dbe6de17f4f7c .

Similar to bug 1325571, it seems like we may want to focus inside the modal when it opens.

Mass wontfix for bugs affecting firefox 52.