Currently, to be a "debug" WebPreference (which really only means it can be enabled for any process for Modern WebKit via NSUserDefaults on Cocoa platforms) the preference needs to be in WebPreferencesDebug.yaml. This means these preferences can't be included in the experimental or internal menus, which isn't ideal. I would propose we replace the separated out WebPreferencesDebug.yaml with a new tag for preferences, perhaps something like "globallyAvailable: true" and merge them into the other files.