Make RenderedRectsForMarkers() to ignore disconnected nodes.

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
index f76a22b37cb8f1d9ffce213a976438a412427ee2..dd38e71754a4795618a2827c87fc129a0188a246 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -32,6 +32,7 @@
 #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"
@@ -213,10 +214,8 @@ static void updateMarkerRenderedRect(const Node& node,
     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();
   }