Clear scroll anchor on all parent scrollers from ScrollAnchor::clear

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 4bb9943626ec9288e050239a16d38ba2be23d34b..b9db6f3ef737d280627669b9e3523e270f08afa8 100644
--- a/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
+++ b/third_party/WebKit/Source/core/layout/ScrollAnchor.cpp
@@ -34,7 +34,7 @@ void ScrollAnchor::setScroller(ScrollableArea* scroller) {
   DCHECK(scroller->isRootFrameViewport() || scroller->isFrameView() ||
          scroller->isPaintLayerScrollableArea());
   m_scroller = scroller;
-  clear();
+  clearForContainingScroller();
 }
 
 // TODO(pilgrim) replace all instances of scrollerLayoutBox with scrollerLayoutBoxItem
@@ -222,7 +222,7 @@ void ScrollAnchor::save() {
           ? VerticalScrollbar
           : HorizontalScrollbar;
   if (m_scroller->scrollPosition(blockLayoutAxis) == 0) {
-    clear();
+    clearForContainingScroller();
     return;
   }
 
@@ -231,7 +231,7 @@ void ScrollAnchor::save() {
     if (!m_anchorObject)
       return;
 
-    m_anchorObject->setIsScrollAnchorObject();
+    m_anchorObject->setIsScrollAnchorObject(true);
     m_savedRelativeOffset =
         computeRelativeOffset(m_anchorObject, m_scroller, m_corner);
   }
@@ -278,7 +278,7 @@ void ScrollAnchor::restore() {
     // Note that we only clear if the adjustment would have been non-zero.
     // This minimizes redundant calls to findAnchor.
     // TODO(skobes): add UMA metric for this.
-    clear();
+    clearForContainingScroller();
 
     DEFINE_STATIC_LOCAL(EnumerationHistogram, suppressedBySanaclapHistogram,
                         ("Layout.ScrollAnchor.SuppressedBySanaclap", 2));
@@ -298,21 +298,27 @@ void ScrollAnchor::restore() {
                     UseCounter::ScrollAnchored);
 }
 
-void ScrollAnchor::clear() {
-  LayoutObject* anchorObject = m_anchorObject;
+void ScrollAnchor::releaseAnchor() {
   m_anchorObject = nullptr;
+}
+
+void ScrollAnchor::clearForContainingScroller() {
+  LayoutObject* anchorObject = m_anchorObject;
+  releaseAnchor();
 
   if (anchorObject)
     anchorObject->maybeClearIsScrollAnchorObject();
 }
 
-bool ScrollAnchor::refersTo(const LayoutObject* layoutObject) const {
-  return m_anchorObject == layoutObject;
+void ScrollAnchor::clear() {
+  if (m_anchorObject)
+    m_anchorObject->clearScrollAnchors();
+  else
+    scrollerLayoutBox(m_scroller)->clearScrollAnchors();
 }
 
-void ScrollAnchor::notifyRemoved(LayoutObject* layoutObject) {
-  if (m_anchorObject == layoutObject)
-    clear();
+bool ScrollAnchor::refersTo(const LayoutObject* layoutObject) const {
+  return m_anchorObject == layoutObject;
 }
 
 }  // namespace blink