ScriptController::processingUserGesture now only returns true for an event handler triggered by a touch end. This is correct in most contexts, and we should have probably done this from the beginning, but it breaks some existing scripts that try to trigger media loading or playback in a touch start handler, so add a media-specific method that allows touch start or touch end events.
rdar://problem/22015509
Created attachment 257969 [details] Proposed patch.
Committed r187688: https://trac.webkit.org/r187688
Plus r187694: https://trac.webkit.org/r187694
Where is ProcessingPotentialUserGesture actually used? For someone just reading WebKit's code, it's not obvious why UserGestureIndicator.h actually needs to define ProcessingPotentialUserGesture and processingUserGestureForMedia().