Implement interest rects for synchronized paint.

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

 /*
  * 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 50 matching lines @@
     GraphicsLayerUpdateSubtree,
 };
 
 // CompositedLayerMapping keeps track of how Layers of the layout tree correspond to
 // GraphicsLayers of the composited layer tree. Each instance of CompositedLayerMapping
 // manages a small cluster of GraphicsLayers and the references to which Layers
 // and paint phases contribute to each GraphicsLayer.
 //
 // Currently (Oct. 2013) there is one CompositedLayerMapping for each Layer,
 // but this is likely to evolve soon.
-class CompositedLayerMapping final : public GraphicsLayerClient {
+class PLATFORM_EXPORT CompositedLayerMapping final : public GraphicsLayerClient {

[chrishtr, 2015/10/09 19:10:29]

This is needed to expose the class for testing across shared library boundaries.

     WTF_MAKE_NONCOPYABLE(CompositedLayerMapping); WTF_MAKE_FAST_ALLOCATED(CompositedPaintLayerMapping);
 public:
     explicit CompositedLayerMapping(PaintLayer&);
     ~CompositedLayerMapping() override;
 
     PaintLayer& owningLayer() const { return m_owningLayer; }
 
     bool updateGraphicsLayerConfiguration();
     void updateGraphicsLayerGeometry(const PaintLayer* compositingContainer, const PaintLayer* compositingStackingContext, Vector<PaintLayer*>& layersNeedingPaintInvalidation);
 
@@ skipping 58 matching lines @@
     bool verifyLayerInSquashingVector(const PaintLayer*);
 #endif
 
     void finishAccumulatingSquashingLayers(size_t nextSquashedLayerIndex);
     void updateRenderingContext();
     void updateShouldFlattenTransform();
 
     // GraphicsLayerClient interface
     void notifyAnimationStarted(const GraphicsLayer*, double monotonicTime, int group) override;
     void notifyTextPainted() override;
+
     void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& clip) const override;
+    void paintContentsIfNeeded(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase) const override;
     bool isTrackingPaintInvalidations() const override;
 
 #if ENABLE(ASSERT)
     void verifyNotPainting() override;
 #endif
 
     LayoutRect contentsBox() const;
 
     GraphicsLayer* layerForHorizontalScrollbar() const { return m_layerForHorizontalScrollbar.get(); }
     GraphicsLayer* layerForVerticalScrollbar() const { return m_layerForVerticalScrollbar.get(); }
@@ skipping 37 matching lines @@
 
     // If there is a squashed layer painting into this CLM that is an ancestor of the given LayoutObject, return it. Otherwise return nullptr.
     const GraphicsLayerPaintInfo* containingSquashedLayer(const LayoutObject*, unsigned maxSquashedLayerIndex);
 
     void updateScrollingBlockSelection();
 
     DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
     String debugName() const { return "CompositedLayerMapping for " + owningLayer().debugName(); }
 
 private:
+    static IntRect computeInterestRect(const GraphicsLayer*, LayoutObject* owningLayoutObject);
+
     static const GraphicsLayerPaintInfo* containingSquashedLayer(const LayoutObject*,  const Vector<GraphicsLayerPaintInfo>& layers, unsigned maxSquashedLayerIndex);
 
     // Helper methods to updateGraphicsLayerGeometry:
     void computeGraphicsLayerParentLocation(const PaintLayer* compositingContainer, const IntRect& ancestorCompositingBounds, IntPoint& graphicsLayerParentLocation);
     void updateSquashingLayerGeometry(const LayoutPoint& offsetFromCompositedAncestor, const IntPoint& graphicsLayerParentLocation, const PaintLayer& referenceLayer, Vector<GraphicsLayerPaintInfo>& layers, GraphicsLayer*, LayoutPoint* offsetFromTransformedAncestor, Vector<PaintLayer*>& layersNeedingPaintInvalidation);
     void updateMainGraphicsLayerGeometry(const IntRect& relativeCompositingBounds, const IntRect& localCompositingBounds, const IntPoint& graphicsLayerParentLocation);
     void updateAncestorClippingLayerGeometry(const PaintLayer* compositingContainer, const IntPoint& snappedOffsetFromCompositedAncestor, IntPoint& graphicsLayerParentLocation);
     void updateOverflowControlsHostLayerGeometry(const PaintLayer* compositingStackingContext, const PaintLayer* compositingContainer);
     void updateChildContainmentLayerGeometry(const IntRect& clippingBox, const IntRect& localCompositingBounds);
     void updateChildTransformLayerGeometry();
@@ skipping 203 matching lines @@
     LayoutRect m_compositedBounds;
 
     LayoutSize m_contentOffsetInCompositingLayer;
     unsigned m_contentOffsetInCompositingLayerDirty : 1;
 
     unsigned m_pendingUpdateScope : 2;
     unsigned m_isMainFrameLayoutViewLayer : 1;
 
     unsigned m_backgroundLayerPaintsFixedRootBackground : 1;
     unsigned m_scrollingContentsAreEmpty : 1;
+
+    friend class CompositedLayerMappingTest;
 };
 
 } // namespace blink
 
 #endif // CompositedLayerMapping_h