Pass UserActivation::Modifiers from nsGlobalWindowOuter::OpenInternal to nsPIWindowWatcher.openWindowWithRemoteTab, through the following interfaces and protocol: * nsPIWindowWatcher.openWindow2 * nsIWindowProvider.provideWindow * PContent.CreateWindow or PContent.CreateWindowInDifferentProcess * nsPIWindowWatcher.openWindowWithRemoteTab Differential Revision: https://phabricator.services.mozilla.com/D197863