Hoist compositorDrivenAcceleratedScrollingEnabled check out of scrollParent

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 20f618d211c61b254a05595db9ba40aaa1bb68a3..c950a88bc770c47aee98a539f26740dec48e8ef5 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -1724,8 +1724,7 @@ void RenderLayer::convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutR
 
 RenderLayer* RenderLayer::scrollParent() const
 {
-    if (!renderer()->compositorDrivenAcceleratedScrollingEnabled())
-        return 0;
+    ASSERT(renderer()->compositorDrivenAcceleratedScrollingEnabled());
 
     // Normal flow elements will be parented under the main scrolling layer, so
     // we don't need a scroll parent/child relationship to get them to scroll.