Alternate way to track first paint

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index d6ca80c9ec6ba09046894ad916749cf3417e68b7..38281267a91f570b9e645286cc792887148f34eb 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -117,6 +117,7 @@ enum InvalidationReason {
     InvalidationScroll,
     InvalidationSelection,
     InvalidationLayer,
+    InvalidationRendererInsertion,
     InvalidationRendererRemoval,
     InvalidationPaintRectangle
 };
@@ -833,9 +834,6 @@ public:
 
     void getTextDecorations(unsigned decorations, AppliedTextDecoration& underline, AppliedTextDecoration& overline, AppliedTextDecoration& linethrough, bool quirksMode = false, bool firstlineStyle = false);
 
-    void setHadPaintInvalidation();
-    bool hadPaintInvalidation() const;
-
     // Return the RenderLayerModelObject in the container chain which is responsible for painting this object, or 0
     // if painting is root-relative. This is the container that should be passed to the 'forPaintInvalidation'
     // methods.
@@ -1015,8 +1013,9 @@ public:
     const LayoutPoint& previousPositionFromPaintInvalidationBacking() const { return m_previousPositionFromPaintInvalidationBacking; }
     void setPreviousPositionFromPaintInvalidationBacking(const LayoutPoint& positionFromPaintInvalidationBacking) { m_previousPositionFromPaintInvalidationBacking = positionFromPaintInvalidationBacking; }
 
-    bool shouldDoFullPaintInvalidation() const { return m_bitfields.shouldDoFullPaintInvalidation(); }
+    bool shouldDoFullPaintInvalidation() const { return m_bitfields.fullPaintInvalidationReason() != InvalidationNone; }
     void setShouldDoFullPaintInvalidation(bool, MarkingBehavior = MarkContainingBlockChain);
+    void setShouldDoFullPaintInvalidationWithReason(InvalidationReason, MarkingBehavior = MarkContainingBlockChain);
 
     bool shouldInvalidateOverflowForPaint() const { return m_bitfields.shouldInvalidateOverflowForPaint(); }
 
@@ -1198,7 +1197,6 @@ private:
     public:
         RenderObjectBitfields(Node* node)
             : m_selfNeedsLayout(false)
-            , m_shouldDoFullPaintInvalidation(false)
             , m_shouldInvalidateOverflowForPaint(false)
             , m_shouldDoFullPaintInvalidationIfSelfPaintingLayer(false)
             // FIXME: We should remove mayNeedPaintInvalidation once we are able to
@@ -1237,12 +1235,12 @@ private:
             , m_selectionState(SelectionNone)
             , m_flowThreadState(NotInsideFlowThread)
             , m_boxDecorationBackgroundState(NoBoxDecorationBackground)
+            , m_fullPaintInvalidationReason(InvalidationNone)
         {
         }
 
-        // 32 bits have been used in the first word, and 11 in the second.
+        // 32 bits have been used in the first word, and 14 in the second.
         ADD_BOOLEAN_BITFIELD(selfNeedsLayout, SelfNeedsLayout);
-        ADD_BOOLEAN_BITFIELD(shouldDoFullPaintInvalidation, ShouldDoFullPaintInvalidation);
         ADD_BOOLEAN_BITFIELD(shouldInvalidateOverflowForPaint, ShouldInvalidateOverflowForPaint);
         ADD_BOOLEAN_BITFIELD(shouldDoFullPaintInvalidationIfSelfPaintingLayer, ShouldDoFullPaintInvalidationIfSelfPaintingLayer);
         ADD_BOOLEAN_BITFIELD(mayNeedPaintInvalidation, MayNeedPaintInvalidation);
@@ -1290,6 +1288,7 @@ private:
         unsigned m_selectionState : 3; // SelectionState
         unsigned m_flowThreadState : 2; // FlowThreadState
         unsigned m_boxDecorationBackgroundState : 2; // BoxDecorationBackgroundState
+        unsigned m_fullPaintInvalidationReason : 4; // InvalidationReason
 
     public:
         bool isOutOfFlowPositioned() const { return m_positionedState == IsOutOfFlowPositioned; }
@@ -1311,6 +1310,9 @@ private:
 
         ALWAYS_INLINE BoxDecorationBackgroundState boxDecorationBackgroundState() const { return static_cast<BoxDecorationBackgroundState>(m_boxDecorationBackgroundState); }
         ALWAYS_INLINE void setBoxDecorationBackgroundState(BoxDecorationBackgroundState s) { m_boxDecorationBackgroundState = s; }
+
+        InvalidationReason fullPaintInvalidationReason() const { return static_cast<InvalidationReason>(m_fullPaintInvalidationReason); }
+        void setFullPaintInvalidationReason(InvalidationReason reason) { m_fullPaintInvalidationReason = reason; }
     };
 
 #undef ADD_BOOLEAN_BITFIELD