Move PinchViewport to the Oilpan heap.

Source/core/frame/PinchViewport.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 43 matching lines @@
 class GraphicsLayerFactory;
 class IntRect;
 class IntSize;
 class LocalFrame;
 
 // Represents the pinch-to-zoom viewport the user is currently seeing the page through. This
 // class corresponds to the InnerViewport on the compositor. It is a ScrollableArea; it's
 // offset is set through the GraphicsLayer <-> CC sync mechanisms. Its contents is the page's
 // main FrameView, which corresponds to the outer viewport. The inner viewport is always contained
 // in the outer viewport and can pan within it.
-class PinchViewport final : public GraphicsLayerClient, public ScrollableArea {
+class PinchViewport final : public NoBaseWillBeGarbageCollectedFinalized<PinchViewport>, public GraphicsLayerClient, public ScrollableArea {
 public:
-    explicit PinchViewport(FrameHost&);
+    static PassOwnPtrWillBeRawPtr<PinchViewport> create(FrameHost& host)
+    {
+        return adoptPtrWillBeNoop(new PinchViewport(host));
+    }
     virtual ~PinchViewport();
+    virtual void trace(Visitor*);
 
     void attachToLayerTree(GraphicsLayer*, GraphicsLayerFactory*);
     GraphicsLayer* rootGraphicsLayer()
     {
         return m_rootTransformLayer.get();
     }
     GraphicsLayer* containerLayer()
     {
         return m_innerViewportContainerLayer.get();
     }
@@ skipping 34 matching lines @@
     // Scroll the main frame and pinch viewport so that the given rect in the
     // top-level document is centered in the viewport. This method will avoid
     // scrolling the pinch viewport unless necessary.
     void scrollIntoView(const FloatRect&);
 
     // Clamp the given point, in document coordinates, to the maximum/minimum
     // scroll extents of the viewport within the document.
     IntPoint clampDocumentOffsetAtScale(const IntPoint& offset, float scale);
 
 private:
+    explicit PinchViewport(FrameHost&);
+
     // ScrollableArea implementation
     virtual bool isActive() const override { return false; }
     virtual int scrollSize(ScrollbarOrientation) const override;
     virtual bool isScrollCornerVisible() const override { return false; }
     virtual IntRect scrollCornerRect() const override { return IntRect(); }
     virtual IntPoint scrollPosition() const override { return flooredIntPoint(m_offset); }
     virtual IntPoint minimumScrollPosition() const override;
     virtual IntPoint maximumScrollPosition() const override;
     virtual int visibleHeight() const override { return visibleRect().height(); };
     virtual int visibleWidth() const override { return visibleRect().width(); };
@@ skipping 14 matching lines @@
     virtual void notifyAnimationStarted(const GraphicsLayer*, double monotonicTime) override;
     virtual void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect& inClip) override;
     virtual String debugName(const GraphicsLayer*) override;
 
     void setupScrollbar(blink::WebScrollbar::Orientation);
     FloatPoint clampOffsetToBoundaries(const FloatPoint&);
     void clampToBoundaries();
 
     LocalFrame* mainFrame() const;
 
-    FrameHost& m_frameHost;
+    FrameHost& frameHost() const
+    {
+        ASSERT(m_frameHost);
+        return *m_frameHost;
+    }
+
+    RawPtrWillBeMember<FrameHost> m_frameHost;
     OwnPtr<GraphicsLayer> m_rootTransformLayer;
     OwnPtr<GraphicsLayer> m_innerViewportContainerLayer;
     OwnPtr<GraphicsLayer> m_pageScaleLayer;
     OwnPtr<GraphicsLayer> m_innerViewportScrollLayer;
     OwnPtr<GraphicsLayer> m_overlayScrollbarHorizontal;
     OwnPtr<GraphicsLayer> m_overlayScrollbarVertical;
     OwnPtr<blink::WebScrollbarLayer> m_webOverlayScrollbarHorizontal;
     OwnPtr<blink::WebScrollbarLayer> m_webOverlayScrollbarVertical;
 
     // Offset of the pinch viewport from the main frame's origin, in CSS pixels.
     FloatPoint m_offset;
     float m_scale;
     IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // PinchViewport_h