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

Source/core/paint/BlockPainter.h

Index: Source/core/paint/BlockPainter.h
diff --git a/Source/core/paint/BlockPainter.h b/Source/core/paint/BlockPainter.h
index 7fdf33d8819a07040e19b2e38a4dbb029e140bfe..e23d9a2cb8de50e139f8c7848062dfc71aa7988f 100644
--- a/Source/core/paint/BlockPainter.h
+++ b/Source/core/paint/BlockPainter.h
@@ -5,6 +5,8 @@
 #ifndef BlockPainter_h
 #define BlockPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
@@ -17,6 +19,7 @@ class LayoutPoint;
 class LayoutRect;
 
 class BlockPainter {
+    STACK_ALLOCATED();
 public:
     BlockPainter(LayoutBlock& block) : m_layoutBlock(block) { }