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

Source/core/paint/EmbeddedObjectPainter.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EmbeddedObjectPainter_h
 #define EmbeddedObjectPainter_h
 
+#include "wtf/Allocator.h"
+
 namespace blink {
 
 struct PaintInfo;
 class FloatRect;
 class Font;
 class LayoutEmbeddedObject;
 class LayoutPoint;
 class Path;
 class TextRun;
 
 class EmbeddedObjectPainter {
+    STACK_ALLOCATED();
 public:
     EmbeddedObjectPainter(LayoutEmbeddedObject& layoutEmbeddedObject) : m_layoutEmbeddedObject(layoutEmbeddedObject) { }
 
     void paintReplaced(const PaintInfo&, const LayoutPoint& paintOffset);
 
 private:
     LayoutEmbeddedObject& m_layoutEmbeddedObject;
 };
 
 } // namespace blink
 
 #endif // EmbeddedObjectPainter_h