Make compositingState explicit

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1234 matching lines @@
 static bool isCandidateForOpaquenessTest(RenderBox* childBox)
 {
     RenderStyle* childStyle = childBox->style();
     if (childStyle->position() != StaticPosition && childBox->containingBlock() != childBox->parent())
         return false;
     if (childStyle->visibility() != VISIBLE || childStyle->shapeOutside())
         return false;
     if (!childBox->width() || !childBox->height())
         return false;
     if (RenderLayer* childLayer = childBox->layer()) {
-        if (childLayer->isComposited())
+        // FIXME: perhaps this could be less conservative?
+        if (childLayer->compositingState() != NotComposited)
             return false;
         // FIXME: Deal with z-index.
         if (!childStyle->hasAutoZIndex())
             return false;
         if (childLayer->hasTransform() || childLayer->isTransparent() || childLayer->hasFilter())
             return false;
     }
     return true;
 }
 
@@ skipping 74 matching lines @@
 
     LayoutRect paintRect = LayoutRect(paintOffset, size());
     paintMaskImages(paintInfo, paintRect);
 }
 
 void RenderBox::paintClippingMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     if (!paintInfo.shouldPaintWithinRoot(this) || style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseClippingMask || paintInfo.context->paintingDisabled())
         return;
 
-    if (!layer() || !layer()->isComposited())
+    if (!layer() || layer()->compositingState() != PaintsIntoOwnBacking)
         return;
 
+    // We should never have this state in this function. A layer with a mask
+    // should have always created its own backing if it became composited.
+    ASSERT(layer()->compositingState() != HasOwnBackingButPaintsIntoAncestor);
+
     LayoutRect paintRect = LayoutRect(paintOffset, size());
     paintInfo.context->fillRect(pixelSnappedIntRect(paintRect), Color::black);
 }
 
 void RenderBox::paintMaskImages(const PaintInfo& paintInfo, const LayoutRect& paintRect)
 {
     // Figure out if we need to push a transparency layer to render our mask.
     bool pushTransparencyLayer = false;
     bool compositedMask = hasLayer() && layer()->hasCompositedMask();
     bool flattenCompositingLayers = view()->frameView() && view()->frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers;
@@ skipping 3420 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore