Invalidate paint of tickmarks on document change

Source/core/dom/RenderedDocumentMarker.h

Index: Source/core/dom/RenderedDocumentMarker.h
diff --git a/Source/core/dom/RenderedDocumentMarker.h b/Source/core/dom/RenderedDocumentMarker.h
index ceb6cb5f360488e316c21708c9568bf9984fbe05..1edb9dd4309d8b44ae718c75a4d15cd99793f92b 100644
--- a/Source/core/dom/RenderedDocumentMarker.h
+++ b/Source/core/dom/RenderedDocumentMarker.h
@@ -41,10 +41,18 @@ public:
 
     bool isRendered() const { return invalidMarkerRect() != m_renderedRect; }
     bool contains(const LayoutPoint& point) const { return isRendered() && m_renderedRect.contains(point); }
-    void setRenderedRect(const LayoutRect& r) { m_renderedRect = r.isEmpty() ? invalidMarkerRect() : r; }
+    bool setRenderedRect(const LayoutRect& r)
+    {
+        const LayoutRect& rect = r.isEmpty() ? invalidMarkerRect() : r;
+        if (rect == m_renderedRect)
+            return false;
+        m_renderedRect = rect;
+        return true;
+    }
+
     const LayoutRect& renderedRect() const { return m_renderedRect; }
 
-    void invalidateRenderedRect() { m_renderedRect = invalidMarkerRect(); }
+    bool invalidateRenderedRect() { return setRenderedRect(invalidMarkerRect()); }
 
 private:
     explicit RenderedDocumentMarker(const DocumentMarker& marker)