Make classes and structures in core/paint fast-allocated.

Source/core/paint/MultiColumnSetPainter.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MultiColumnSetPainter_h
 #define MultiColumnSetPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
 class LayoutPoint;
 class LayoutMultiColumnSet;
 
 class MultiColumnSetPainter {
+    STACK_ALLOCATED();
 public:
     MultiColumnSetPainter(LayoutMultiColumnSet& layoutMultiColumnSet) : m_layoutMultiColumnSet(layoutMultiColumnSet) { }
     void paintObject(const PaintInfo&, const LayoutPoint& paintOffset);
 
 private:
     void paintColumnRules(const PaintInfo&, const LayoutPoint& paintOffset);
 
     LayoutMultiColumnSet& m_layoutMultiColumnSet;
 };
 
 } // namespace blink
 
 #endif // MultiColumnSetPainter_h