Drop InvalidationSetMode.

Source/core/css/invalidation/DescendantInvalidationSet.h

Index: Source/core/css/invalidation/DescendantInvalidationSet.h
diff --git a/Source/core/css/invalidation/DescendantInvalidationSet.h b/Source/core/css/invalidation/DescendantInvalidationSet.h
index 64f06b126ffc6120ca615a85cf434e07172a8f19..aa85f9ff6f766ac0194261b1242d9c3bb7fef847 100644
--- a/Source/core/css/invalidation/DescendantInvalidationSet.h
+++ b/Source/core/css/invalidation/DescendantInvalidationSet.h
@@ -67,6 +67,9 @@ public:
     void setTreeBoundaryCrossing() { m_treeBoundaryCrossing = true; }
     bool treeBoundaryCrossing() const { return m_treeBoundaryCrossing; }
 
+    void setInsertionPointCrossing() { m_insertionPointCrossing = true; }
+    bool insertionPointCrossing() const { return m_insertionPointCrossing; }
+
     void setCustomPseudoInvalid() { m_customPseudoInvalid = true; }
     bool customPseudoInvalid() const { return m_customPseudoInvalid; }
 
@@ -100,6 +103,9 @@ private:
 
     // If true, the invalidation must traverse into ShadowRoots with this set.
     unsigned m_treeBoundaryCrossing : 1;
+
+    // If true, insertion point descendants must be invalidated.
+    unsigned m_insertionPointCrossing : 1;
 };
 
 } // namespace blink