Don't bubble scrolls across boundary when scrolling to anchor

Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 1797 matching lines @@
     if (!anchorNode)
         return;
 
     if (!anchorNode->renderer())
         return;
 
     LayoutRect rect;
     if (anchorNode != m_frame->document())
         rect = anchorNode->boundingBox();
 
+    RefPtrWillBeRawPtr<LocalFrame> boundaryFrame = m_frame->document()->findUnsafeParentScrollPropagationBoundary();
+
+    if (boundaryFrame)
+        boundaryFrame->view()->setSafeToPropagateScrollToParent(false);
+
     // Scroll nested layers and frames to reveal the anchor.
     // Align to the top and to the closest side (this matches other browsers).
     anchorNode->renderer()->scrollRectToVisible(rect, ScrollAlignment::alignToEdgeIfNeeded, ScrollAlignment::alignTopAlways);
 
+    if (boundaryFrame)
+        boundaryFrame->view()->setSafeToPropagateScrollToParent(true);
+
     if (AXObjectCache* cache = m_frame->document()->existingAXObjectCache())
         cache->handleScrolledToAnchor(anchorNode.get());
 
     // scrollRectToVisible can call into setScrollPosition(), which resets m_maintainScrollPositionAnchor.
     m_maintainScrollPositionAnchor = anchorNode;
 }
 
 bool FrameView::updateWidgets()
 {
     // This is always called from updateWidgetsTimerFired.
@@ skipping 1187 matching lines @@
     IntSize visibleSize = expandedIntSize(visibleContentSizeF);
 
     IntPoint maximumOffset(
         contentsWidth() - visibleSize.width() - scrollOrigin().x(),
         contentsHeight() - visibleSize.height() - scrollOrigin().y());
     maximumOffset.clampNegativeToZero();
     return maximumOffset;
 }
 
 } // namespace blink