Revert "Make compositingState explicit (re-land #2 with bogus ASSERT removed)"

Source/core/rendering/RenderView.cpp

Index: Source/core/rendering/RenderView.cpp
diff --git a/Source/core/rendering/RenderView.cpp b/Source/core/rendering/RenderView.cpp
index 2d2dcbd99b8ca8562f8f0bb3ab2e910d416c02ac..618bf5f7f0cf5715774d10095ede2b1366b4c26d 100644
--- a/Source/core/rendering/RenderView.cpp
+++ b/Source/core/rendering/RenderView.cpp
@@ -439,6 +439,11 @@ void RenderView::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
     paintObject(paintInfo, paintOffset);
 }
 
+static inline bool isComposited(RenderObject* object)
+{
+    return object->hasLayer() && toRenderLayerModelObject(object)->layer()->isComposited();
+}
+
 static inline bool rendererObscuresBackground(RenderObject* rootObject)
 {
     if (!rootObject)
@@ -450,7 +455,7 @@ static inline bool rendererObscuresBackground(RenderObject* rootObject)
         || style->hasTransform())
         return false;
 
-    if (rootObject->compositingState() == PaintsIntoOwnBacking)
+    if (isComposited(rootObject))
         return false;
 
     const RenderObject* rootRenderer = rootObject->rendererForRootBackground();