Implement bounce suppression in ScrollAnchor.

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 04df4e8ddb7f0078263cf85711bfff7c009dbcbb..9453bccf1cd52459af4bb7abc26a04c4d8993088 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -2758,10 +2758,10 @@ static bool findReferencingScrollAnchors(LayoutObject* layoutObject, FindReferen
     while (layer) {
         if (PaintLayerScrollableArea* scrollableArea = layer->getScrollableArea()) {
             ScrollAnchor& anchor = scrollableArea->scrollAnchor();
-            if (anchor.anchorObject() == layoutObject) {
+            if (anchor.refersTo(layoutObject)) {
                 found = true;
                 if (behavior == Clear)
-                    anchor.clear();
+                    anchor.notifyRemoved(layoutObject);
                 else
                     return true;
             }
@@ -2770,10 +2770,10 @@ static bool findReferencingScrollAnchors(LayoutObject* layoutObject, FindReferen
     }
     if (FrameView* view = layoutObject->frameView()) {
         ScrollAnchor& anchor = view->scrollAnchor();
-        if (anchor.anchorObject() == layoutObject) {
+        if (anchor.refersTo(layoutObject)) {
             found = true;
             if (behavior == Clear)
-                anchor.clear();
+                anchor.notifyRemoved(layoutObject);
         }
     }
     return found;