Bug 1209852 - Re-enable scroll-inactive-layers-2.html now that the underlying issue has been fixed. r=mstange

This also modifies the reftest list so that the harness doesn't load the same
page twice unnecessarily.

--HG--
extra : commitid : KKCE0y2cscF

layout/reftests/invalidation/reftest.list

@@ -39,8 +39,8 @@ pref(layout.animated-image-layers.enabled,true) skip-if(Android||gtkWidget) == t
 == filter-userspace-offset.svg?offsetContainer=foreignObject&mask=userSpace-at100 filter-userspace-offset.svg
 == filter-userspace-offset.svg?offsetContainer=rect&filter=matrix-fillPaint-boundingBox filter-userspace-offset.svg
 == filter-userspace-offset.svg?offsetContainer=rect&filter=matrix-fillPaint-userSpace-at100 filter-userspace-offset.svg
-== scroll-inactive-layers.html scroll-inactive-layers.html
-skip-if(asyncPan) == scroll-inactive-layers-2.html scroll-inactive-layers-2.html
+!= scroll-inactive-layers.html about:blank
+!= scroll-inactive-layers-2.html about:blank
 != inactive-layertree-visible-region-1.html about:blank
 != inactive-layertree-visible-region-2.html about:blank
 != transform-floating-point-invalidation.html about:blank