Fix virtual/override/final usage in Source/core/layout/.

Source/core/layout/LayoutFlowThread.h

Index: Source/core/layout/LayoutFlowThread.h
diff --git a/Source/core/layout/LayoutFlowThread.h b/Source/core/layout/LayoutFlowThread.h
index 264bcb22319e1a522db2ca78448594c236fed906..64e45b9afff32424c640c959a5788ec787c77b11 100644
--- a/Source/core/layout/LayoutFlowThread.h
+++ b/Source/core/layout/LayoutFlowThread.h
@@ -48,19 +48,19 @@ typedef ListHashSet<LayoutMultiColumnSet*> LayoutMultiColumnSetList;
 class CORE_EXPORT LayoutFlowThread: public LayoutBlockFlow {
 public:
     LayoutFlowThread();
-    virtual ~LayoutFlowThread() { }
+    ~LayoutFlowThread() override { }
 
-    virtual bool isLayoutFlowThread() const override final { return true; }
+    bool isLayoutFlowThread() const final { return true; }
     virtual bool isLayoutMultiColumnFlowThread() const { return false; }
     virtual bool isLayoutPagedFlowThread() const { return false; }
 
-    virtual bool supportsPaintInvalidationStateCachedOffsets() const override { return false; }
+    bool supportsPaintInvalidationStateCachedOffsets() const override { return false; }
 
-    virtual void layout() override;
+    void layout() override;
 
     // Always create a Layer for the LayoutFlowThread so that we
     // can easily avoid drawing the children directly.
-    virtual DeprecatedPaintLayerType layerTypeRequired() const override final { return NormalDeprecatedPaintLayer; }
+    DeprecatedPaintLayerType layerTypeRequired() const final { return NormalDeprecatedPaintLayer; }
 
     // Skip past a column spanner during flow thread layout. Spanners are not laid out inside the
     // flow thread, since the flow thread is not in a spanner's containing block chain (since the
@@ -72,12 +72,12 @@ public:
     virtual void flowThreadDescendantStyleWillChange(LayoutObject*, StyleDifference, const ComputedStyle& newStyle) { }
     virtual void flowThreadDescendantStyleDidChange(LayoutObject*, StyleDifference, const ComputedStyle& oldStyle) { }
 
-    virtual bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override final;
+    bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) final;
 
     virtual void addColumnSetToThread(LayoutMultiColumnSet*) = 0;
     virtual void removeColumnSetFromThread(LayoutMultiColumnSet*);
 
-    virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
+    void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
 
     bool hasColumnSets() const { return m_multiColumnSetList.size(); }
 
@@ -85,7 +85,7 @@ public:
     void invalidateColumnSets();
     bool hasValidColumnSetInfo() const { return !m_columnSetsInvalidated && !m_multiColumnSetList.isEmpty(); }
 
-    virtual void mapRectToPaintInvalidationBacking(const LayoutBoxModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const override;
+    void mapRectToPaintInvalidationBacking(const LayoutBoxModelObject* paintInvalidationContainer, LayoutRect&, const PaintInvalidationState*) const override;
 
     LayoutUnit pageLogicalHeightForOffset(LayoutUnit);
     LayoutUnit pageRemainingLogicalHeightForOffset(LayoutUnit, PageBoundaryRule = IncludePageBoundary);