Invalidate paint of tickmarks on document change

Source/core/dom/RenderedDocumentMarker.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 23 matching lines @@
 
 class RenderedDocumentMarker final : public DocumentMarker {
 public:
     static PassOwnPtrWillBeRawPtr<RenderedDocumentMarker> create(const DocumentMarker& marker)
     {
         return adoptPtrWillBeNoop(new RenderedDocumentMarker(marker));
     }
 
     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)
         : DocumentMarker(marker)
         , m_renderedRect(invalidMarkerRect())
     {
     }
 
     static const LayoutRect& invalidMarkerRect()
     {
         static const LayoutRect rect = LayoutRect(-1, -1, -1, -1);
         return rect;
     }
 
     LayoutRect m_renderedRect;
 };
 
 DEFINE_TYPE_CASTS(RenderedDocumentMarker, DocumentMarker, marker, true, true);
 
 } // namespace blink
 
 WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(blink::RenderedDocumentMarker);
 
 #endif