Youtube videos do not play in full screen on iPad

[Tieu Vu]

Steps to reproduce

1. Launch Focus
2. Past and GO on address bar: https://www.youtube.com/watch?v=CwA1VWP0Ldw
3. Tap on full screen button

Expected behavior

• Videos should play in full screen.

Actual behavior

• The full screen button is greyed out.

Device & build information

• Device: IPAD 12.9 gen 6

┆Issue is synchronized with this Jira Task

[Sergey Zolotarev]

For me it happens only after I reload the tab. If I simply open the same video twice, the full screen button remains active.

Upon pressing on the grayed-out full screen button, a tooltiop appears saying: Full screen mode is not supported by this browser

Turning Tracking Protection off has no effect.

[Sergey Zolotarev]

Adding

addScript(forResource: "FullScreen", injectionTime: .atDocumentStart, forMainFrameOnly: true)

to

focus-ios/Blockzilla/Modules/WebView/WebViewController.swift

Line 238 in f16bfcf

 addScript(forResource: "FullScreen", injectionTime: .atDocumentEnd, forMainFrameOnly: true) 

seems to fix it