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

Source/core/paint/HTMLCanvasPainter.h

Index: Source/core/paint/HTMLCanvasPainter.h
diff --git a/Source/core/paint/HTMLCanvasPainter.h b/Source/core/paint/HTMLCanvasPainter.h
index e1e7550f0044a08723868c5a5b5041d16aadfc66..5d2196dc3ff085589558aee9f56fad4e2eb7b859 100644
--- a/Source/core/paint/HTMLCanvasPainter.h
+++ b/Source/core/paint/HTMLCanvasPainter.h
@@ -5,6 +5,8 @@
 #ifndef HTMLCanvasPainter_h
 #define HTMLCanvasPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
@@ -12,6 +14,7 @@ class LayoutPoint;
 class LayoutHTMLCanvas;
 
 class HTMLCanvasPainter {
+    STACK_ALLOCATED();
 public:
     HTMLCanvasPainter(LayoutHTMLCanvas& layoutHTMLCanvas) : m_layoutHTMLCanvas(layoutHTMLCanvas) { }
     void paintReplaced(const PaintInfo&, const LayoutPoint&);