Remove Scrollbar dependency on AXObjectCache

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 4166305b390ab3e34ed552a4fec1d304b73ffa59..2a7718c2e04dbcf51034e4696286c1df962d1900 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -3498,4 +3498,20 @@ void FrameView::setLayoutSizeInternal(const IntSize& size)
     contentsResized();
 }
 
+void FrameView::didAddScrollbar(Scrollbar* scrollbar, ScrollbarOrientation orientation)
+{
+    ScrollableArea::didAddScrollbar(scrollbar, orientation);
+    if (AXObjectCache* cache = axObjectCache())
+        cache->handleScrollbarUpdate(this);
+}
+
+void FrameView::willRemoveScrollbar(Scrollbar* scrollbar, ScrollbarOrientation orientation)
+{
+    ScrollableArea::willRemoveScrollbar(scrollbar, orientation);
+    if (AXObjectCache* cache = axObjectCache()) {
+        cache->remove(scrollbar);
+        cache->handleScrollbarUpdate(this);
+    }
+}
+
 } // namespace WebCore