On iOS 11 WKWebView loads much slower if it is not a part of the view hierarchy. This is more-likely a system issue, however it is important to have a workaround until Apple fixes the bug.
BUG: 739390, 703222, 734669 Change-Id: I09d5c3ffadee44d3a5a6d834d4b5f0839b20f50b Reviewed-on: https://chromium-review.googlesource.com/566183
a7c2ee6 Always add WKWebView to the view hierarchy on iOS 11.
ios/web/web_state/ui/crw_web_controller.mm | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)