Fix scroll anchoring during viewport resize.

third_party/WebKit/Source/web/RotationViewportAnchor.cpp

 // 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.
 
 #include "web/RotationViewportAnchor.h"
 
 #include "core/dom/ContainerNode.h"
 #include "core/dom/Node.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 66 matching lines @@
     inner.setLocation(innerOrigin);
 }
 
 } // namespace
 
 RotationViewportAnchor::RotationViewportAnchor(
     FrameView& rootFrameView,
     VisualViewport& visualViewport,
     const FloatSize& anchorInInnerViewCoords,
     PageScaleConstraintsSet& pageScaleConstraintsSet)
-    : ViewportAnchor(rootFrameView, visualViewport)
+    : m_rootFrameView(&rootFrameView)
+    , m_visualViewport(&visualViewport)
     , m_anchorInInnerViewCoords(anchorInInnerViewCoords)
     , m_pageScaleConstraintsSet(pageScaleConstraintsSet)
 {
     setAnchor();
 }
 
 RotationViewportAnchor::~RotationViewportAnchor()
 {
     restoreToAnchor();
 }
@@ skipping 106 matching lines @@
     anchorOffsetFromNode.scale(m_anchorInNodeCoords.width(), m_anchorInNodeCoords.height());
     FloatPoint anchorPoint = FloatPoint(currentNodeBounds.location()) + anchorOffsetFromNode;
 
     // Compute the new origin point relative to the new anchor point
     FloatSize anchorOffsetFromOrigin = innerSize;
     anchorOffsetFromOrigin.scale(m_anchorInInnerViewCoords.width(), m_anchorInInnerViewCoords.height());
     return anchorPoint - anchorOffsetFromOrigin;
 }
 
 } // namespace blink