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

Source/core/paint/SVGRootInlineBoxPainter.h

Index: Source/core/paint/SVGRootInlineBoxPainter.h
diff --git a/Source/core/paint/SVGRootInlineBoxPainter.h b/Source/core/paint/SVGRootInlineBoxPainter.h
index bc722a970ee5900f1186edbbc110862e0a263927..febd0e1bb234411e7e910b7d158b2f2466490a91 100644
--- a/Source/core/paint/SVGRootInlineBoxPainter.h
+++ b/Source/core/paint/SVGRootInlineBoxPainter.h
@@ -5,6 +5,8 @@
 #ifndef SVGRootInlineBoxPainter_h
 #define SVGRootInlineBoxPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
@@ -12,6 +14,7 @@ class LayoutPoint;
 class SVGRootInlineBox;
 
 class SVGRootInlineBoxPainter {
+    STACK_ALLOCATED();
 public:
     SVGRootInlineBoxPainter(SVGRootInlineBox& svgRootInlineBox) : m_svgRootInlineBox(svgRootInlineBox) { }