--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -674,20 +674,18 @@ private:
   DECL_GFX_PREF(Live, "layout.display-list.retain.verify",     LayoutVerifyRetainDisplayList, bool, false);
   DECL_GFX_PREF(Live, "layout.display-list.retain.verify.order", LayoutVerifyRetainDisplayListOrder, bool, false);
   DECL_GFX_PREF(Live, "layout.display-list.rebuild-frame-limit", LayoutRebuildFrameLimit, uint32_t, 500);
   DECL_GFX_PREF(Live, "layout.display-list.dump",              LayoutDumpDisplayList, bool, false);
   DECL_GFX_PREF(Live, "layout.display-list.dump-content",      LayoutDumpDisplayListContent, bool, false);
   DECL_GFX_PREF(Live, "layout.display-list.dump-parent",       LayoutDumpDisplayListParent, bool, false);
   DECL_GFX_PREF(Live, "layout.display-list.show-rebuild-area", LayoutDisplayListShowArea, bool, false);
 
-  DECL_GFX_PREF(Once, "layout.simple-event-region-items",      SimpleEventRegionItems, bool, true);
+  DECL_GFX_PREF(Once, "layout.frame_rate",                     LayoutFrameRate, int32_t, -1);
   DECL_GFX_PREF(Once, "layout.less-event-region-items",        LessEventRegionItems, bool, true);
-
-  DECL_GFX_PREF(Once, "layout.frame_rate",                     LayoutFrameRate, int32_t, -1);
   DECL_GFX_PREF(Live, "layout.min-active-layer-size",          LayoutMinActiveLayerSize, int, 64);
   DECL_GFX_PREF(Once, "layout.paint_rects_separately",         LayoutPaintRectsSeparately, bool, true);
 
   // This and code dependent on it should be removed once containerless scrolling looks stable.
   DECL_GFX_PREF(Once, "layout.scroll.root-frame-containers",   LayoutUseContainersForRootFrames, bool, true);
   // This pref is to be set by test code only.
   DECL_GFX_PREF(Live, "layout.scrollbars.always-layerize-track", AlwaysLayerizeScrollbarTrackTestOnly, bool, false);
   DECL_GFX_PREF(Live, "layout.smaller-painted-layers",         LayoutSmallerPaintedLayers, bool, false);

--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -1030,18 +1030,17 @@ nsDisplayListBuilder::nsDisplayListBuild
       mHitTestIsForVisibility(false),
       mIsBuilding(false),
       mInInvalidSubtree(false),
       mDisablePartialUpdates(false),
       mPartialBuildFailed(false)
 {
   MOZ_COUNT_CTOR(nsDisplayListBuilder);
 
-  mBuildCompositorHitTestInfo = mAsyncPanZoomEnabled && IsForPainting() &&
-    (gfxVars::UseWebRender() || gfxPrefs::SimpleEventRegionItems());
+  mBuildCompositorHitTestInfo = mAsyncPanZoomEnabled && IsForPainting();
 
   mLessEventRegionItems = gfxPrefs::LessEventRegionItems();
 
   nsPresContext* pc = aReferenceFrame->PresContext();
   nsIPresShell *shell = pc->PresShell();
   if (pc->IsRenderingOnlySelection()) {
     nsCOMPtr<nsISelectionController> selcon(do_QueryInterface(shell));
     if (selcon) {