Don't bubble scrolls across boundary when scrolling to anchor

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index 3a1981bc031046ce0b6779f4b965aa3e0eb6b868..a140c32ea05ba89083284aa63bd4967f1e89bb4f 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -1815,10 +1815,18 @@ void FrameView::scrollToAnchor()
     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());