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

Source/core/paint/SVGMaskPainter.h

Index: Source/core/paint/SVGMaskPainter.h
diff --git a/Source/core/paint/SVGMaskPainter.h b/Source/core/paint/SVGMaskPainter.h
index a5c975eb51edf14abb61ca2a963cf7886a366740..f0c386d6a5234431b0055042395405f1eae44013 100644
--- a/Source/core/paint/SVGMaskPainter.h
+++ b/Source/core/paint/SVGMaskPainter.h
@@ -6,6 +6,7 @@
 #define SVGMaskPainter_h
 
 #include "platform/geometry/FloatRect.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -14,6 +15,7 @@ class LayoutObject;
 class LayoutSVGResourceMasker;
 
 class SVGMaskPainter {
+    STACK_ALLOCATED();
 public:
     SVGMaskPainter(LayoutSVGResourceMasker& mask) : m_mask(mask) { }