Put rare PaintLayer fields into PaintLayerRareData

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 331 matching lines @@
     }
 }
 
 void CompositedLayerMapping::updateCompositingReasons()
 {
     // All other layers owned by this mapping will have the same compositing reason
     // for their lifetime, so they are initialized only when created.
     m_graphicsLayer->setCompositingReasons(m_owningLayer.compositingReasons());
 }
 
-bool CompositedLayerMapping::owningLayerClippedByLayerNotAboveCompositedAncestor(PaintLayer* scrollParent)
+bool CompositedLayerMapping::owningLayerClippedByLayerNotAboveCompositedAncestor(const PaintLayer* scrollParent)
 {
     if (!m_owningLayer.parent())
         return false;
 
     const PaintLayer* compositingAncestor = m_owningLayer.enclosingLayerWithCompositedLayerMapping(ExcludeSelf);
     if (!compositingAncestor)
         return false;
 
     const LayoutObject* clippingContainer = m_owningLayer.clippingContainer();
     if (!clippingContainer)
@@ skipping 12 matching lines @@
     // updateAncestorClippingLayerGeometry will fail as the clip rect will be
     // infinite.
     // FIXME: this should use cached clip rects, but this sometimes give
     // inaccurate results (and trips the ASSERTS in PaintLayerClipper).
     ClipRectsContext clipRectsContext(compositingAncestor, UncachedClipRects, IgnoreOverlayScrollbarSize);
     clipRectsContext.setIgnoreOverflowClip();
     IntRect parentClipRect = pixelSnappedIntRect(m_owningLayer.clipper().backgroundClipRect(clipRectsContext).rect());
     return parentClipRect != LayoutRect::infiniteIntRect();
 }
 
-PaintLayer* CompositedLayerMapping::scrollParent()
+const PaintLayer* CompositedLayerMapping::scrollParent()
 {
-    PaintLayer* scrollParent = m_owningLayer.scrollParent();
+    const PaintLayer* scrollParent = m_owningLayer.scrollParent();
     if (scrollParent && !scrollParent->needsCompositedScrolling())
         return nullptr;
     return scrollParent;
 }
 
 bool CompositedLayerMapping::updateGraphicsLayerConfiguration()
 {
     ASSERT(m_owningLayer.compositor()->lifecycle().state() == DocumentLifecycle::InCompositingUpdate);
 
     // Note carefully: here we assume that the compositing state of all descendants have been updated already,
@@ skipping 17 matching lines @@
 
     if (updateForegroundLayer(compositor->needsContentsCompositingLayer(&m_owningLayer)))
         layerConfigChanged = true;
 
     bool needsDescendantsClippingLayer = compositor->clipsCompositingDescendants(&m_owningLayer);
 
     // Our scrolling layer will clip.
     if (m_owningLayer.needsCompositedScrolling())
         needsDescendantsClippingLayer = false;
 
-    PaintLayer* scrollParent = this->scrollParent();
+    const PaintLayer* scrollParent = this->scrollParent();
 
     // This is required because compositing layers are parented according to the z-order hierarchy, yet
     // clipping goes down the layoutObject hierarchy. Thus, a PaintLayer can be clipped by a
     // PaintLayer that is an ancestor in the layoutObject hierarchy, but a sibling in the z-order
     // hierarchy. Further, that sibling need not be composited at all. In such scenarios, an ancestor
     // clipping layer is necessary to apply the composited clip for this layer.
     bool needsAncestorClip = owningLayerClippedByLayerNotAboveCompositedAncestor(scrollParent);
 
     if (updateClippingLayers(needsAncestorClip, needsDescendantsClippingLayer))
         layerConfigChanged = true;
@@ skipping 1222 matching lines @@
         layerChanged = true;
         if (scrollingCoordinator) {
             scrollingCoordinator->scrollableAreaScrollLayerDidChange(m_owningLayer.scrollableArea());
             scrollingCoordinator->scrollableAreasDidChange();
         }
     }
 
     return layerChanged;
 }
 
-static void updateScrollParentForGraphicsLayer(GraphicsLayer* layer, GraphicsLayer* topmostLayer, PaintLayer* scrollParent, ScrollingCoordinator* scrollingCoordinator)
+static void updateScrollParentForGraphicsLayer(GraphicsLayer* layer, GraphicsLayer* topmostLayer, const PaintLayer* scrollParent, ScrollingCoordinator* scrollingCoordinator)
 {
     if (!layer)
         return;
 
     // Only the topmost layer has a scroll parent. All other layers have a null scroll parent.
     if (layer != topmostLayer)
         scrollParent = 0;
 
     scrollingCoordinator->updateScrollParentForGraphicsLayer(layer, scrollParent);
 }
 
-void CompositedLayerMapping::updateScrollParent(PaintLayer* scrollParent)
+void CompositedLayerMapping::updateScrollParent(const PaintLayer* scrollParent)
 {
     if (ScrollingCoordinator* scrollingCoordinator = scrollingCoordinatorFromLayer(m_owningLayer)) {
         GraphicsLayer* topmostLayer = childForSuperlayers();
         updateScrollParentForGraphicsLayer(m_squashingContainmentLayer.get(), topmostLayer, scrollParent, scrollingCoordinator);
         updateScrollParentForGraphicsLayer(m_ancestorClippingLayer.get(), topmostLayer, scrollParent, scrollingCoordinator);
         updateScrollParentForGraphicsLayer(m_graphicsLayer.get(), topmostLayer, scrollParent, scrollingCoordinator);
     }
 }
 
-static void updateClipParentForGraphicsLayer(GraphicsLayer* layer, GraphicsLayer* topmostLayer, PaintLayer* clipParent, ScrollingCoordinator* scrollingCoordinator)
+static void updateClipParentForGraphicsLayer(GraphicsLayer* layer, GraphicsLayer* topmostLayer, const PaintLayer* clipParent, ScrollingCoordinator* scrollingCoordinator)
 {
     if (!layer)
         return;
 
     // Only the topmost layer has a scroll parent. All other layers have a null scroll parent.
     if (layer != topmostLayer)
         clipParent = 0;
 
     scrollingCoordinator->updateClipParentForGraphicsLayer(layer, clipParent);
 }
 
-void CompositedLayerMapping::updateClipParent(PaintLayer* scrollParent)
+void CompositedLayerMapping::updateClipParent(const PaintLayer* scrollParent)
 {
     if (owningLayerClippedByLayerNotAboveCompositedAncestor(scrollParent))
         return;
 
-    PaintLayer* clipParent = m_owningLayer.clipParent();
+    const PaintLayer* clipParent = m_owningLayer.clipParent();
     if (clipParent)
         clipParent = clipParent->enclosingLayerWithCompositedLayerMapping(IncludeSelf);
 
     if (ScrollingCoordinator* scrollingCoordinator = scrollingCoordinatorFromLayer(m_owningLayer)) {
         GraphicsLayer* topmostLayer = childForSuperlayers();
         updateClipParentForGraphicsLayer(m_squashingContainmentLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
         updateClipParentForGraphicsLayer(m_ancestorClippingLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
         updateClipParentForGraphicsLayer(m_graphicsLayer.get(), topmostLayer, clipParent, scrollingCoordinator);
     }
 }
@@ skipping 864 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink