Move sticky position constraints update to the pre-paint tree walk.

third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
index c831a2605904e4ae941b716ace1e67b280e12d7b..24332fe0ebdc39ae3afc7e08dc70fa784b472ba2 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
@@ -102,7 +102,8 @@ void CompositingInputsUpdater::updateRecursive(PaintLayer* layer,
   layer->updateAncestorOverflowLayer(info.lastOverflowClipLayer);
   if (info.lastOverflowClipLayer && layer->needsCompositingInputsUpdate() &&
       layer->layoutObject()->style()->position() == StickyPosition) {
-    if (info.lastOverflowClipLayer != previousOverflowLayer) {
+    if (info.lastOverflowClipLayer != previousOverflowLayer &&
+        !RuntimeEnabledFeatures::rootLayerScrollingEnabled()) {
       // Old ancestor scroller should no longer have these constraints.
       ASSERT(!previousOverflowLayer ||
              !previousOverflowLayer->getScrollableArea()