Bug 1973726 - Set DOM file path for webkitRelativePath. r=sefeng,geckoview-reviewers,webidl,smaug,ohall
Actually, there is no way to set webkitRelativePath from JavaScript.
Since GeckoView's folder picker handles virtual file data, we need to
set relative path from JavaScript directly.
A content URI of System storage document provider only allow file data
access from file/folder picker, so there is no way to test it on
geckoivew-junit.
Also, after landing bug 1591640, GVE always crash when using folder
picker. So this includes a fix for it.
Differential Revision: https://phabricator.services.mozilla.com/D255615
<!DOCTYPE html><htmlclass="reftest-wait"><metaname="viewport"content="width=device-width, minimum-scale=0.5"><style>html{overflow-x:hidden;}html,body{margin:0;width:100%;height:100%;}div{height:100%;position:absolute;}</style><divid="green"style="background: green; width: 100%;"></div><divstyle="background: blue; width: 100%;"></div><script>document.addEventListener('MozReftestInvalidate',()=>{// Grow width to generate overflow-x:hidden area but the content height is// 100vh so that we don't scale down the contents (bug 1508177).green.style.width='200%';requestAnimationFrame(()=>{document.documentElement.classList.remove('reftest-wait');});});</script></html>