[No submit][SPInvalidation] Track paint offset change

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

Index: third_party/WebKit/Source/core/paint/ObjectPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/ObjectPainter.cpp b/third_party/WebKit/Source/core/paint/ObjectPainter.cpp
index 98c18abd55fff2f1a4611890f8a62084acaef77c..164cf74deca966d4d776031cfcd27046285964d3 100644
--- a/third_party/WebKit/Source/core/paint/ObjectPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/ObjectPainter.cpp
@@ -694,4 +694,24 @@ void ObjectPainter::paintAllPhasesAtomically(const PaintInfo& paintInfo,
   m_layoutObject.paint(info, paintOffset);
 }
 
+#if DCHECK_IS_ON()
+void ObjectPainter::doCheckPaintOffset(const PaintInfo& paintInfo,
+                                       const LayoutPoint& paintOffset) {
+  if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() ||
+      paintInfo.getGlobalPaintFlags() != GlobalPaintNormalPhase ||
+      paintInfo.context.getPaintController().isSkippingCache() ||
+      m_layoutObject.isSVG())
+    return;
+
+  LayoutPoint adjustedPaintOffset = paintOffset;
+  if (m_layoutObject.isBox())
+    adjustedPaintOffset += toLayoutBox(m_layoutObject).location();
+  DCHECK(m_layoutObject.previousPaintOffset() == adjustedPaintOffset)
+      << m_layoutObject.debugName() << " paint offset mismatch:"
+      << " paint property paint offset: "
+      << m_layoutObject.previousPaintOffset().toString()
+      << " painter paint offset: " << adjustedPaintOffset.toString();
+}
+#endif
+
 }  // namespace blink