Make compositingState explicit

Source/core/page/FrameView.cpp

Index: Source/core/page/FrameView.cpp
diff --git a/Source/core/page/FrameView.cpp b/Source/core/page/FrameView.cpp
index 26a418a8b757791bdc66d9f80c07dbea17c435c8..4c5c57af4d6aed83bc0e7e3628ab1e8f702bd045 100644
--- a/Source/core/page/FrameView.cpp
+++ b/Source/core/page/FrameView.cpp
@@ -1250,7 +1250,7 @@ void FrameView::updateCanBlitOnScrollRecursively()
 bool FrameView::contentsInCompositedLayer() const
 {
     RenderView* renderView = this->renderView();
-    if (renderView && renderView->isComposited()) {
+    if (renderView && renderView->compositingState() == PaintsIntoOwnBacking) {
         GraphicsLayer* layer = renderView->layer()->backing()->graphicsLayer();
         if (layer && layer->drawsContent())
             return true;
@@ -1364,7 +1364,7 @@ bool FrameView::scrollContentsFastPath(const IntSize& scrollDelta, const IntRect
         // Composited layers may still actually paint into their ancestor.
         // If that happens, the viewport constrained object needs to be
         // repainted on scroll.
-        if (layer->isComposited() && !layer->backing()->paintsIntoCompositedAncestor())
+        if (layer->compositingState() == PaintsIntoOwnBacking)
             continue;
 
         if (layer->viewportConstrainedNotCompositedReason() == RenderLayer::NotCompositedForBoundsOutOfView