[DNS] Don't adjust the scroll position if the anchor element changes in size

third_party/WebKit/Source/core/layout/ScrollAnchor.cpp

Index: third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
diff --git a/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp b/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
index dbefd1b256907f3901c8ce3c78e5c3360262ac94..596bc788cf2f4ab8a5e466e9b0406315fdf4267a 100644
--- a/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
+++ b/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
@@ -163,6 +163,7 @@ void ScrollAnchor::save()
 
     m_anchorObject->setIsScrollAnchorObject();
     m_savedRelativeOffset = computeRelativeOffset(m_anchorObject, m_scroller, m_corner);
+    m_savedAnchorSize =  toLayoutBox(m_anchorObject)->size();
 }
 
 void ScrollAnchor::restore()
@@ -170,6 +171,11 @@ void ScrollAnchor::restore()
     if (!m_anchorObject)
         return;
 
+    if (toLayoutBox(m_anchorObject)->size() != m_savedAnchorSize) {
+        clear();
+        return;
+    }
+
     LayoutSize adjustment = computeRelativeOffset(m_anchorObject, m_scroller, m_corner) - m_savedRelativeOffset;
     if (!adjustment.isZero()) {
         m_scroller->setScrollPosition(