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

Source/core/paint/SVGInlineFlowBoxPainter.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 SVGInlineFlowBoxPainter_h
 #define SVGInlineFlowBoxPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
 class LayoutPoint;
 class SVGInlineFlowBox;
 
 class SVGInlineFlowBoxPainter {
+    STACK_ALLOCATED();
 public:
     SVGInlineFlowBoxPainter(SVGInlineFlowBox& svgInlineFlowBox) : m_svgInlineFlowBox(svgInlineFlowBox) { }
 
     void paintSelectionBackground(const PaintInfo&);
     void paint(const PaintInfo&, const LayoutPoint&);
 
 private:
     SVGInlineFlowBox& m_svgInlineFlowBox;
 };
 
 } // namespace blink
 
 #endif // SVGInlineFlowBoxPainter_h