Move PreviousBoxGeometries from BoxPaintInvalidator into LayoutBox::m_rareData

third_party/WebKit/Source/core/layout/LayoutBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple Inc. 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 58 matching lines @@
         m_snapContainer(nullptr),
         m_snapAreas(nullptr) {}
 
   // For spanners, the spanner placeholder that lays us out within the multicol
   // container.
   LayoutMultiColumnSpannerPlaceholder* m_spannerPlaceholder;
 
   LayoutUnit m_overrideLogicalContentWidth;
   LayoutUnit m_overrideLogicalContentHeight;
 
-  bool m_hasOverrideContainingBlockContentLogicalWidth;
-  bool m_hasOverrideContainingBlockContentLogicalHeight;
+  bool m_hasOverrideContainingBlockContentLogicalWidth : 1;
+  bool m_hasOverrideContainingBlockContentLogicalHeight : 1;
+  bool m_hasPreviousOtherBoxGeometries : 1;
+
   LayoutUnit m_overrideContainingBlockContentLogicalWidth;
   LayoutUnit m_overrideContainingBlockContentLogicalHeight;
 
   LayoutUnit m_offsetToNextPage;
 
   LayoutUnit m_paginationStrut;
 
   LayoutBlock* m_percentHeightContainer;
   // For snap area, the owning snap container.
   LayoutBox* m_snapContainer;
   // For snap container, the descendant snap areas that contribute snap
   // points.
   std::unique_ptr<SnapAreaSet> m_snapAreas;
 
   SnapAreaSet& ensureSnapAreas() {
     if (!m_snapAreas)
       m_snapAreas = WTF::wrapUnique(new SnapAreaSet);
 
     return *m_snapAreas;
   }
+
+  // Used by BoxPaintInvalidator. Stores the previous content box size and
+  // layout overflow rect after the last paint invalidation.
+  // These are valid if m_hasPreviousOtherBoxGeometries is true.
+  LayoutSize m_previousContentBoxSize;
+  LayoutRect m_previousLayoutOverflowRect;
 };
 
 // LayoutBox implements the full CSS box model.
 //
 // LayoutBoxModelObject only introduces some abstractions for LayoutInline and
 // LayoutBox. The logic for the model is in LayoutBox, e.g. the storage for the
 // rectangle and offset forming the CSS box (m_frameRect) and the getters for
 // the different boxes.
 //
 // LayoutBox is also the uppermost class to support scrollbars, however the
@@ skipping 200 matching lines @@
       setHeight(size);
     else
       setWidth(size);
   }
 
   LayoutPoint location() const { return m_frameRect.location(); }
   LayoutSize locationOffset() const {
     return LayoutSize(m_frameRect.x(), m_frameRect.y());
   }
   LayoutSize size() const { return m_frameRect.size(); }
-  LayoutSize previousSize() const { return m_previousSize; }
   IntSize pixelSnappedSize() const { return m_frameRect.pixelSnappedSize(); }
 
   void setLocation(const LayoutPoint& location) {
     if (location == m_frameRect.location())
       return;
     m_frameRect.setLocation(location);
     locationChanged();
   }
 
   // The ancestor box that this object's location and physicalLocation are
@@ skipping 972 matching lines @@
   bool intersectsVisibleViewport() const;
 
   bool hasNonCompositedScrollbars() const final;
 
   void ensureIsReadyForPaintInvalidation() override;
 
   virtual bool hasControlClip() const { return false; }
 
   class MutableForPainting : public LayoutObject::MutableForPainting {
    public:
-    void setPreviousSize(const LayoutSize& size) {
-      static_cast<LayoutBox&>(m_layoutObject).m_previousSize = size;
+    void savePreviousSize() { layoutBox().m_previousSize = layoutBox().size(); }
+    void savePreviousOtherBoxGeometries() {

[mstensho (USE GERRIT), 2017/02/21 17:51:51]

Pretty unusual to inline the rareData setters. Could you move it to .cpp?

[Xianzhu, 2017/02/21 18:14:48]

Done.

+      auto& rareData = layoutBox().ensureRareData();
+      rareData.m_hasPreviousOtherBoxGeometries = true;
+      rareData.m_previousContentBoxSize = layoutBox().contentBoxRect().size();
+      rareData.m_previousLayoutOverflowRect = layoutBox().layoutOverflowRect();
+    }
+    void clearPreviousOtherBoxGeometries() {
+      if (layoutBox().m_rareData)
+        layoutBox().m_rareData->m_hasPreviousOtherBoxGeometries = false;
     }
 
    protected:
     friend class LayoutBox;
     MutableForPainting(const LayoutBox& box)
         : LayoutObject::MutableForPainting(box) {}
+    LayoutBox& layoutBox() { return static_cast<LayoutBox&>(m_layoutObject); }
   };
+
   MutableForPainting getMutableForPainting() const {
     return MutableForPainting(*this);
   }
 
+  LayoutSize previousSize() const { return m_previousSize; }
+  LayoutSize previousContentBoxSize() const {
+    return m_rareData && m_rareData->m_hasPreviousOtherBoxGeometries
+               ? m_rareData->m_previousContentBoxSize
+               : previousSize();
+  }
+  LayoutRect previousLayoutOverflowRect() const {
+    return m_rareData && m_rareData->m_hasPreviousOtherBoxGeometries
+               ? m_rareData->m_previousLayoutOverflowRect
+               : LayoutRect(LayoutPoint(), previousSize());
+  }
+
  protected:
   virtual LayoutRect controlClipRect(const LayoutPoint&) const {
     return LayoutRect();
   }
 
   void willBeDestroyed() override;
 
   void insertedIntoTree() override;
   void willBeRemovedFromTree() override;
 
@@ skipping 316 matching lines @@
          breakValue == EBreakBetween::kLeft ||
          breakValue == EBreakBetween::kPage ||
          breakValue == EBreakBetween::kRecto ||
          breakValue == EBreakBetween::kRight ||
          breakValue == EBreakBetween::kVerso;
 }
 
 }  // namespace blink
 
 #endif  // LayoutBox_h