Oilpan: Fix a raw reference in FramePainter.

Source/core/paint/FramePainter.h

 // Copyright 2014 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 FramePainter_h
 #define FramePainter_h
 
 #include "core/paint/PaintPhase.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
 class FrameView;
 class GraphicsContext;
 class IntRect;
 class Scrollbar;
 
 class FramePainter {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(FramePainter);
 public:
-    FramePainter(FrameView& frameView) : m_frameView(frameView) { }
+    explicit FramePainter(FrameView& frameView) : m_frameView(&frameView) { }
 
     void paint(GraphicsContext*, const GlobalPaintFlags, const IntRect&);
     void paintScrollbars(GraphicsContext*, const IntRect&);
     void paintContents(GraphicsContext*, const GlobalPaintFlags, const IntRect& damageRect);
     void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
 
 private:
     void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&);
 
-    FrameView& m_frameView;
+    FrameView& frameView();
+
+    RawPtrWillBeMember<FrameView> m_frameView;
     static bool s_inPaintContents;
 };
 
 } // namespace blink
 
 #endif // FramePainter_h