1466338 - `window.outerHeight` reports wrong value if executed in newly opened tab in minimized window

Status: UNCONFIRMED

(Core :: DOM: Core & HTML, defect, P3)

Description

[juraj.masiar]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
Build ID: 20180530184300

Steps to reproduce:

1) create web-extension with a custom page that prints to console `window.outerHeight` value upon opening

2) open new Firefox window and minimize it

3) open debugging console for the add-on and execute this code (replace the "NAME_OF_YOUR_CUSTOM_PAGE" with your add-on custom html page):
`browser.windows.getAll().then(windows => windows.filter(w => w.type === browser.windows.WindowType.NORMAL).filter(w => w.state === browser.windows.WindowState.MINIMIZED).slice(0, 1).forEach(w => browser.tabs.create({url: '/NAME_OF_YOUR_CUSTOM_PAGE.html', windowId: w.id})))`


Actual results:

Very low value is printed into console, in my case only 28.


Expected results:

Correct value should be printed depending on the screen size.

Note that once the window is not minimized anymore, the correct value is reported.