Save previous paint offset in LayoutObject

Source/core/paint/LayoutObjectDrawingRecorder.h

Index: Source/core/paint/LayoutObjectDrawingRecorder.h
diff --git a/Source/core/paint/LayoutObjectDrawingRecorder.h b/Source/core/paint/LayoutObjectDrawingRecorder.h
index b0da6bb6a3d838da9605d842919c131470ba19d6..3634a315b60bc444316a9e4a566a94c6c5056dae 100644
--- a/Source/core/paint/LayoutObjectDrawingRecorder.h
+++ b/Source/core/paint/LayoutObjectDrawingRecorder.h
@@ -25,8 +25,7 @@ class LayoutObjectDrawingRecorder final {
 public:
     static bool useCachedDrawingIfPossible(GraphicsContext& context, const LayoutObject& layoutObject, DisplayItem::Type displayItemType, const LayoutPoint& paintOffset)
     {
-        // TODO(pdr): The paint offset cache should be stored on LayoutObject but is temporarily on the DisplayItemList.
-        if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && !context.displayItemList()->paintOffsetIsUnchanged(layoutObject.displayItemClient(), paintOffset))
+        if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && layoutObject.previousPaintOffset() != paintOffset)
             return false;
         if (layoutObject.fullPaintInvalidationReason() == PaintInvalidationDelayedFull)
             return false;
@@ -40,8 +39,7 @@ public:
 
     static bool useCachedDrawingIfPossible(GraphicsContext& context, const InlineBox& inlineBox, DisplayItem::Type displayItemType, const LayoutPoint& paintOffset)
     {
-        // TODO(pdr): The paint offset cache should be stored on LayoutObject but is temporarily on the DisplayItemList.
-        if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && !context.displayItemList()->paintOffsetIsUnchanged(inlineBox.displayItemClient(), paintOffset))
+        if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && inlineBox.layoutObject().previousPaintOffset() != paintOffset)
             return false;
         return DrawingRecorder::useCachedDrawingIfPossible(context, inlineBox, displayItemType);
     }
@@ -53,7 +51,7 @@ public:
 
     LayoutObjectDrawingRecorder(GraphicsContext& context, const LayoutObject& layoutObject, DisplayItem::Type displayItemType, const FloatRect& clip, const LayoutPoint& paintOffset)
     {
-        updatePaintOffsetIfNeeded(context.displayItemList(), layoutObject, paintOffset);
+        updatePaintOffsetIfNeeded(context.displayItemList(), layoutObject, layoutObject, paintOffset);
         // We may paint a delayed-invalidation object before it's actually invalidated.
         if (layoutObject.fullPaintInvalidationReason() == PaintInvalidationDelayedFull)
             m_cacheSkipper.emplace(context);
@@ -74,7 +72,7 @@ public:
 
     LayoutObjectDrawingRecorder(GraphicsContext& context, const InlineBox& inlineBox, DisplayItem::Type displayItemType, const FloatRect& clip, const LayoutPoint& paintOffset)
     {
-        updatePaintOffsetIfNeeded(context.displayItemList(), inlineBox, paintOffset);
+        updatePaintOffsetIfNeeded(context.displayItemList(), inlineBox.layoutObject(), inlineBox, paintOffset);
         m_drawingRecorder.emplace(context, inlineBox, displayItemType, clip);
     }
 
@@ -92,14 +90,13 @@ public:
 #endif
 
 private:
-    static void updatePaintOffsetIfNeeded(DisplayItemList* displayItemList, const DisplayItemClientWrapper& client, const LayoutPoint& paintOffset)
+    static void updatePaintOffsetIfNeeded(DisplayItemList* displayItemList, const LayoutObject& layoutObject, const DisplayItemClientWrapper& client, const LayoutPoint& paintOffset)
     {
         if (!RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled())
             return;
 
-        // TODO(pdr): The paint offset cache should be stored on LayoutObject but is temporarily on the DisplayItemList.
-        if (!displayItemList->paintOffsetIsUnchanged(client.displayItemClient(), paintOffset)) {
-            displayItemList->recordPaintOffset(client.displayItemClient(), paintOffset);
+        if (layoutObject.previousPaintOffset() != paintOffset) {
+            layoutObject.setPreviousPaintOffset(paintOffset);
             displayItemList->invalidatePaintOffset(client);
         } else {
             ASSERT(!displayItemList->paintOffsetWasInvalidated(client.displayItemClient()) || !displayItemList->clientCacheIsValid(client.displayItemClient()));