Reduce invalidation on children-needs-layout containers

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 579d0067ccf0c72776770269ab2e7ba50542e070..7f5047e1ebe5fe7c304a0f7cfc1263e233c0618f 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -407,6 +407,9 @@ public:
             setNeedsLayout();
     }
 
+    bool hasNothingToPaint() const { return m_bitfields.hasNothingToPaint(); }
+    void setHasNothingToPaint(bool b) { return m_bitfields.setHasNothingToPaint(b); }
+
     enum FlowThreadState {
         NotInsideFlowThread = 0,
         InsideOutOfFlowThread = 1,
@@ -525,6 +528,8 @@ public:
     bool hasBackground() const { return style()->hasBackground(); }
     bool hasEntirelyFixedBackground() const;
 
+    bool needsLayoutBecauseOfChildren() const { return needsLayout() && !selfNeedsLayout() && !needsPositionedMovementLayout() && !needsSimplifiedNormalFlowLayout(); }
+
     bool needsLayout() const
     {
         return m_bitfields.selfNeedsLayout() || m_bitfields.normalChildNeedsLayout() || m_bitfields.posChildNeedsLayout()
@@ -1124,6 +1129,7 @@ private:
             , m_hasCounterNodeMap(false)
             , m_everHadLayout(false)
             , m_ancestorLineBoxDirty(false)
+            , m_hasNothingToPaint(false)
             , m_childrenInline(false)
             , m_hasColumns(false)
             , m_layoutDidGetCalled(false)
@@ -1163,6 +1169,8 @@ private:
         ADD_BOOLEAN_BITFIELD(everHadLayout, EverHadLayout);
         ADD_BOOLEAN_BITFIELD(ancestorLineBoxDirty, AncestorLineBoxDirty);
 
+        ADD_BOOLEAN_BITFIELD(hasNothingToPaint, HasNothingToPaint);
+
         // from RenderBlock
         ADD_BOOLEAN_BITFIELD(childrenInline, ChildrenInline);
         ADD_BOOLEAN_BITFIELD(hasColumns, HasColumns);