As discussed in bug #191656 it might be needed that scrollbarLogicalWidth() and scrollbarLogicalHeight() returns zero on iOS. Some weird issues on iOS caused that the patch for #191656 got rollout, to make it pass all tests in iOS and iOS Simulator. To fix it temporary we added a "#if !PLATFORM(IOS_FAMILY)" there.
Does scrollbarIntrusion() do what you want?
Created attachment 355390 [details] Patch for checking iOS EWS
Comment on attachment 355390 [details] Patch for checking iOS EWS View in context: https://bugs.webkit.org/attachment.cgi?id=355390&action=review > Source/WebCore/rendering/RenderGrid.cpp:1011 > + borderAndPadding += layer()->scrollbarIntrusion().width(); I guess you can just use layer()->horizontalScrollbarIntrusion()?
Created attachment 355394 [details] Trying horizontalScrollbarIntrusion() as suggested by fwang
The tests seems to render fine for me when running directly in the Safari simulator, so I wonder whether it's something specific to the test runner.
Comment on attachment 355394 [details] Trying horizontalScrollbarIntrusion() as suggested by fwang Attachment 355394 [details] did not pass ios-sim-ews (ios-simulator-wk2): Output: https://webkit-queues.webkit.org/results/10098603 New failing tests: imported/w3c/web-platform-tests/css/css-grid/grid-model/grid-container-scrollbar-001.html
Created attachment 355409 [details] Archive of layout-test-results from ews124 for ios-simulator-wk2 The attached test failures were seen while running run-webkit-tests on the ios-sim-ews. Bot: ews124 Port: ios-simulator-wk2 Platform: Mac OS X 10.13.6