[SPv2] Track paint offset change

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

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1566 matching lines @@
   // container (*not* the graphics layer that paints this object).
   LayoutRect previousVisualRectIncludingCompositedScrolling(
       const LayoutBoxModelObject& paintInvalidationContainer) const;
 
   // The returned rect does *not* account for composited scrolling.
   const LayoutRect& previousVisualRect() const { return m_previousVisualRect; }
 
   // Called when the previous visual rect(s) is no longer valid.
   virtual void clearPreviousVisualRects();
 
+  const LayoutPoint& previousPaintOffset() const {
+    return m_previousPaintOffset;
+  }
+
   // Only adjusts if the paint invalidation container is not a composited
   // scroller.
   void adjustPreviousPaintInvalidationForScrollIfNeeded(
       const DoubleSize& scrollDelta);
 
   PaintInvalidationReason fullPaintInvalidationReason() const {
     return m_bitfields.fullPaintInvalidationReason();
   }
   bool shouldDoFullPaintInvalidation() const {
     return m_bitfields.fullPaintInvalidationReason() != PaintInvalidationNone;
@@ skipping 75 matching lines @@
     void setShouldDoFullPaintInvalidation(PaintInvalidationReason reason) {
       m_layoutObject.setShouldDoFullPaintInvalidation(reason);
     }
     void ensureIsReadyForPaintInvalidation() {
       m_layoutObject.ensureIsReadyForPaintInvalidation();
     }
 
     void setPreviousVisualRect(const LayoutRect& r) {
       m_layoutObject.setPreviousVisualRect(r);
     }
+    void setPreviousPaintOffset(const LayoutPoint& p) {
+      m_layoutObject.m_previousPaintOffset = p;

[chrishtr, 2016/11/10 18:42:00]

DCHECK(slimmingPaintV2Enabled())

[Xianzhu, 2016/11/10 22:51:50]

Added DCHECK(slimmingPaintInvalidationEnabled()). This is also used to track
paint offset change for partial paint property tree update on SPv1.

+    }
     void setHasPreviousLocationInBacking(bool b) {
       m_layoutObject.m_bitfields.setHasPreviousLocationInBacking(b);
     }
     void setPreviousBackgroundObscured(bool b) {
       m_layoutObject.setPreviousBackgroundObscured(b);
     }
     void clearPreviousVisualRects() {
       m_layoutObject.clearPreviousVisualRects();
     }
    protected:
@@ skipping 644 matching lines @@
     m_bitfields.setSelfNeedsOverflowRecalcAfterStyleChange(true);
   }
   void setChildNeedsOverflowRecalcAfterStyleChange() {
     m_bitfields.setChildNeedsOverflowRecalcAfterStyleChange(true);
   }
 
  private:
   // Store state between styleWillChange and styleDidChange
   static bool s_affectsParentBlock;
 
-  // This stores the visual rect from the previous frame. This rect does *not*
-  // account for composited scrolling. See
+  // This stores the visual rect computed by the latest paint invalidation.
+  // This rect does *not* account for composited scrolling. See
   // adjustVisualRectForCompositedScrolling().
   LayoutRect m_previousVisualRect;
+
+  // This stores the paint offset computed by the latest paint property tree
+  // building. It is relative to the containing transform space. It is the same
+  // offset that will be used to paint the object on SPv2.
+  LayoutPoint m_previousPaintOffset;
 };
 
 // FIXME: remove this once the layout object lifecycle ASSERTS are no longer
 // hit.
 class DeprecatedDisableModifyLayoutTreeStructureAsserts {
   STACK_ALLOCATED();
   WTF_MAKE_NONCOPYABLE(DeprecatedDisableModifyLayoutTreeStructureAsserts);
 
  public:
   DeprecatedDisableModifyLayoutTreeStructureAsserts();
@@ skipping 201 matching lines @@
 CORE_EXPORT void showLineTree(const blink::LayoutObject*);
 CORE_EXPORT void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 CORE_EXPORT void showLayoutTree(const blink::LayoutObject* object1,
                                 const blink::LayoutObject* object2);
 
 #endif
 
 #endif  // LayoutObject_h