Fix scroll anchoring during viewport resize.

third_party/WebKit/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"
 
 namespace blink {
 
 class FrameView;
 class Node;
 class PageScaleConstraintsSet;
 class VisualViewport;
 
 // 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 {
+class RotationViewportAnchor {
     STACK_ALLOCATED();
 public:
     RotationViewportAnchor(FrameView& rootFrameView, VisualViewport&, const FloatSize& anchorInInnerViewCoords, PageScaleConstraintsSet&);
     ~RotationViewportAnchor();
 
 private:
     void setAnchor();
     void restoreToAnchor();
 
     FloatPoint getInnerOrigin(const FloatSize& innerSize) const;
 
     void computeOrigins(const FloatSize& innerSize, IntPoint& mainFrameOffset, FloatPoint& visualViewportOffset) const;
 
+    Member<FrameView> m_rootFrameView;
+    Member<VisualViewport> m_visualViewport;
+
     float m_oldPageScaleFactor;
     float m_oldMinimumPageScaleFactor;
 
     // Inner viewport origin in the reference frame of the document in CSS pixels
     FloatPoint m_visualViewportInDocument;
 
     // Inner viewport origin in the reference frame of the outer viewport
     // normalized to the outer viewport size.
     FloatSize m_normalizedVisualViewportOffset;
 
     Member<Node> m_anchorNode;
     LayoutRect m_anchorNodeBounds;
 
     FloatSize m_anchorInInnerViewCoords;
     FloatSize m_anchorInNodeCoords;
 
     PageScaleConstraintsSet& m_pageScaleConstraintsSet;
 };
 
 } // namespace blink
 
 #endif // RotationViewportAnchor_h