132705 2014-05-08 13:27:41 -0700 window.screenX can't be cached 2014-05-21 11:20:46 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) Unspecified Unspecified RESOLVED FIXED P2 Normal --- 132721 132751 132916 132918 132922 1 mhahnenberg mhahnenberg kling oldest_to_newest 1007755 0 mhahnenberg 2014-05-08 13:27:41 -0700 There are a number of reasons for this. (1) JSDOMWindow claims HasImpureGetOwnPropertySlot (2) JSDOMWindow uses setCustom for many of its properties instead of setCacheableCustom. (3) JSDOMWindow needs to not cache in some cases, even where it says it might be able to. This is dependent on getting rid of HasImpureGetOwnPropertySlot. 1007846 1 mhahnenberg 2014-05-08 18:01:17 -0700 There are a number of other properties on JSDOMWindow that can't be cached, but I picked screenX as the "canonical example". 1010801 2 mhahnenberg 2014-05-21 11:20:46 -0700 This is done.