Make RenderedRectsForMarkers() to ignore disconnected nodes.

third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
@@ skipping 195 matching lines @@
                                      RenderedDocumentMarker& marker) {
   Range* range = Range::create(node.document());
   // The offsets of the marker may be out-dated, so check for exceptions.
   DummyExceptionStateForTesting exceptionState;
   range->setStart(&const_cast<Node&>(node), marker.startOffset(),
                   exceptionState);
   if (!exceptionState.hadException()) {
     range->setEnd(&const_cast<Node&>(node), marker.endOffset(),
                   IGNORE_EXCEPTION_FOR_TESTING);
   }
-  if (!exceptionState.hadException()) {
+  if (!exceptionState.hadException() && range->isConnected()) {

[yosin_UTC9, 2017/04/04 01:20:39]

This change should not be in this patch.
If we need to satisfy this condition, we should check it call sites,
|node.isConnection()|, actually
there is only one call site
|DocumentMarkerController::renderedRectsForMarkers()|, and should have
|DCEHCK(node.isConnected()| in this function.

Example:
static void updateMarkerRenderedRect(const Node& node, ...) {
  DCHECK(node.isConnected()) << node;
  ...

Vector<IntRect> DocumentMarkerController::renderedRectsForMarkers(...) {
   ...
  for (MarkerMap::iterator nodeIterator = m_markers.begin();
       nodeIterator != end; ++nodeIterator) {
    // inner loop; process each marker in this node
    const Node& node = *nodeIterator->key;
    if (!node.isConnected())
      continue;
  ...
}

[Hwanseung Lee, 2017/04/05 15:21:30]

Done.

     // TODO(yosin): Once we have a |EphemeralRange| version of |boundingBox()|,
     // we should use it instead of |Range| version.
     marker.setRenderedRect(LayoutRect(range->boundingBox()));
   } else {
     marker.nullifyRenderedRect();
   }
   range->dispose();
 }
 
 // Markers are stored in order sorted by their start offset.
@@ skipping 656 matching lines @@
 }
 
 }  // namespace blink
 
 #ifndef NDEBUG
 void showDocumentMarkers(const blink::DocumentMarkerController* controller) {
   if (controller)
     controller->showMarkers();
 }
 #endif