Refactor to simplify how layerType is stored on PaintLayers.

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 117 matching lines @@
     , compositingReasons(CompositingReasonNone)
     , squashingDisallowedReasons(SquashingDisallowedReasonsNone)
     , groupedMapping(nullptr)
 {
 }
 
 PaintLayerRareData::~PaintLayerRareData()
 {
 }
 
-PaintLayer::PaintLayer(LayoutBoxModelObject* layoutObject, PaintLayerType type)
-    : m_layerType(type)
-    , m_hasSelfPaintingLayerDescendant(false)
+PaintLayer::PaintLayer(LayoutBoxModelObject* layoutObject)
+    : m_hasSelfPaintingLayerDescendant(false)
     , m_hasSelfPaintingLayerDescendantDirty(false)
     , m_isRootLayer(layoutObject->isLayoutView())
     , m_visibleContentStatusDirty(true)
     , m_hasVisibleContent(false)
     , m_visibleDescendantStatusDirty(false)
     , m_hasVisibleDescendant(false)
     , m_hasVisibleNonLayerContent(false)
 #if ENABLE(ASSERT)
     , m_needsPositionUpdate(true)
 #endif
@@ skipping 2295 matching lines @@
         if (childLayer->backgroundIsKnownToBeOpaqueInRect(childLocalRect))
             return true;
     }
     return false;
 }
 
 bool PaintLayer::shouldBeSelfPaintingLayer() const
 {
     if (layoutObject()->isLayoutPart() && toLayoutPart(layoutObject())->requiresAcceleratedCompositing())
         return true;
-    return m_layerType == NormalPaintLayer
+    return layoutObject()->layerTypeRequired() == NormalPaintLayer
         || (m_scrollableArea && m_scrollableArea->hasOverlayScrollbars())
         || needsCompositedScrolling();
 }
 
 void PaintLayer::updateSelfPaintingLayer()
 {
     bool isSelfPaintingLayer = shouldBeSelfPaintingLayer();
     if (this->isSelfPaintingLayer() == isSelfPaintingLayer)
         return;
 
@@ skipping 446 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif