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 14 matching lines @@
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "core/editing/markers/DocumentMarkerController.h"
 
 #include "core/dom/Node.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Range.h"
 #include "core/dom/Text.h"
+#include "core/editing/VisibleUnits.h"
 #include "core/editing/iterators/TextIterator.h"
 #include "core/editing/markers/RenderedDocumentMarker.h"
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutObject.h"
 #include <algorithm>
 
 #ifndef NDEBUG
 #include <stdio.h>
 #endif
 
@@ skipping 161 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()) {
-    // TODO(yosin): Once we have a |EphemeralRange| version of |boundingBox()|,
-    // we should use it instead of |Range| version.
-    marker.setRenderedRect(LayoutRect(range->boundingBox()));
+  if (!exceptionState.hadException() && range->isConnected()) {
+    marker.setRenderedRect(LayoutRect(boundingBox(EphemeralRange(range))));

[yosin_UTC9, 2017/03/30 01:23:17]

Note: Intention of this TODO is using |EphemeralRange| through out this function

instead of just here.

Anyway, this patch is good start point, I recommend to split this patch into two
patches:

1. In-place change of Range::textRects() and boundingBox() to EphemeralRange
version in "Range.cpp"
In-place change with some unit tests for sanity.
  (in-place change) Rename/Change Range::textRects() to static Vector<IntRect>
computeTextRects(const EphemeralRange&)
  (in-place change) Rename/Change Range::boundingBox() to InRect
computeBoundingBox(const EphmeralRange&)
  Range::boundinBox() { return computeBondingBox(EphemeralRange(this)); }

Since Range::textRects() is private member of Range and it is used only in
Range::boundingBox(), we don't need to expose computeTextRects().

2. Rewrite  updateMarkerRenderedRect() to use EphemeralRange instead of Range

Note: We would like to have Flat Tree version of computeBoundingBox() too for
using it in TextFinder.

   } else {
     marker.nullifyRenderedRect();
   }
   range->dispose();
 }
 
 // Markers are stored in order sorted by their start offset.
 // Markers of the same type do not overlap each other.
 
 void DocumentMarkerController::addMarker(Node* node,
@@ skipping 653 matching lines @@
 }
 
 }  // namespace blink
 
 #ifndef NDEBUG
 void showDocumentMarkers(const blink::DocumentMarkerController* controller) {
   if (controller)
     controller->showMarkers();
 }
 #endif