Affected versions

• 66.0a1
• 65.0

Affected platforms

• Windows 10x64
• Ubuntu 16.4

Steps to reproduce

1. Install Firefo
2. Open any web page
3. From hamburger menu click to display the window in full screen (or hit F11)
4. Go to Customize
5. Change the Density from Normal to Touch, Normal
6. Point to mouse cursor to view the auto-hide toolbar

Expected result

• Toolbar should be visible when pointing the mouse cursor

Actual result

• Auto-hide toolbar is not visible when pointing the mouse cursor after changing Density from Customize

**Regression range

• Will return with regression range ASA

(In reply to Gabi Cheta [:Gabi] Release Desktop QA from comment #0)

• Will return with regression range ASA

I expect we'll need the regression range to set the correct priority here. However, I also expect this is a "regression" from when the density stuff was implemented, ie this has "always" been broken.

(In reply to :Gijs (limited availability until Tue 29; he/him) from comment #1)

(In reply to Gabi Cheta [:Gabi] Release Desktop QA from comment #0)

• Will return with regression range ASA

I expect we'll need the regression range to set the correct priority here. However, I also expect this is a "regression" from when the density stuff was implemented, ie this has "always" been broken.

I've runned a bisection with mozregression and the issue reproduces ever since the Density options were added to Customize in 2017-07-02.