Turn ViewportAnchors into stack allocated objects.

Source/web/RotationViewportAnchor.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 RotationViewportAnchor_h
 #define RotationViewportAnchor_h
 
 #include "platform/geometry/FloatSize.h"
 #include "platform/geometry/IntPoint.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/heap/Handle.h"
 #include "web/ViewportAnchor.h"
-#include "wtf/RefCounted.h"
 
 namespace blink {
 
 class FrameView;
 class Node;
 class PageScaleConstraintsSet;
 class PinchViewport;
 
 // The rotation anchor provides a way to anchor a viewport origin to a DOM node.
 // In particular, the user supplies an anchor point (in view coordinates, e.g.,
 // (0, 0) == viewport origin, (0.5, 0) == viewport top center). The anchor point
 // tracks the underlying DOM node; as the node moves or the view is resized, the
 // viewport anchor maintains its orientation relative to the node, and the
 // viewport origin maintains its orientation relative to the anchor. If there is
 // no node or it is lost during the resize, we fall back to the resize anchor
 // logic.
 class RotationViewportAnchor : public ViewportAnchor {
+    STACK_ALLOCATED();
 public:
-    RotationViewportAnchor(
-        FrameView& rootFrameView,
-        PinchViewport&,
-        const FloatSize& anchorInInnerViewCoords,
-        PageScaleConstraintsSet&);
-    virtual ~RotationViewportAnchor() { }
-
-    virtual void setAnchor();
-    virtual void restoreToAnchor();
+    RotationViewportAnchor(FrameView& rootFrameView, PinchViewport&, const FloatSize& anchorInInnerViewCoords, PageScaleConstraintsSet&);
+    ~RotationViewportAnchor();
 
 private:
+    void setAnchor();
+    void restoreToAnchor();
+
     FloatPoint getInnerOrigin(const FloatSize& innerSize) const;
 
-    void computeOrigins(const FloatSize& innerSize,
-        IntPoint& mainFrameOffset, FloatPoint& pinchViewportOffset) const;
+    void computeOrigins(const FloatSize& innerSize, IntPoint& mainFrameOffset, FloatPoint& pinchViewportOffset) const;
 
     float m_oldPageScaleFactor;
     float m_oldMinimumPageScaleFactor;
 
     // Inner viewport origin in the reference frame of the document in CSS pixels
     FloatPoint m_pinchViewportInDocument;
 
     // Inner viewport origin in the reference frame of the outer viewport
     // normalized to the outer viewport size.
     FloatSize m_normalizedPinchViewportOffset;
 
-    RefPtrWillBePersistent<Node> m_anchorNode;
+    RefPtrWillBeMember<Node> m_anchorNode;
     LayoutRect m_anchorNodeBounds;
 
     FloatSize m_anchorInInnerViewCoords;
     FloatSize m_anchorInNodeCoords;
 
     PageScaleConstraintsSet& m_pageScaleConstraintsSet;
 };
 
 } // namespace blink
 
-#endif
+#endif // RotationViewportAnchor_h