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

Source/core/paint/MultiColumnSetPainter.h

Index: Source/core/paint/MultiColumnSetPainter.h
diff --git a/Source/core/paint/MultiColumnSetPainter.h b/Source/core/paint/MultiColumnSetPainter.h
index 0a047da59aa3efa6c7a8a5c62426f295eb0c0f85..939b82423428e452e59aabe0525e191268e78465 100644
--- a/Source/core/paint/MultiColumnSetPainter.h
+++ b/Source/core/paint/MultiColumnSetPainter.h
@@ -5,6 +5,8 @@
 #ifndef MultiColumnSetPainter_h
 #define MultiColumnSetPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
@@ -12,6 +14,7 @@ class LayoutPoint;
 class LayoutMultiColumnSet;
 
 class MultiColumnSetPainter {
+    STACK_ALLOCATED();
 public:
     MultiColumnSetPainter(LayoutMultiColumnSet& layoutMultiColumnSet) : m_layoutMultiColumnSet(layoutMultiColumnSet) { }
     void paintObject(const PaintInfo&, const LayoutPoint& paintOffset);