Do not traverse nodes not having a layout object while searching editable visible position.

Source/core/editing/htmlediting.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 212 matching lines @@
     return PositionType();
 }
 
 Position nextCandidate(const Position& position)
 {
     return nextCandidateAlgorithm<EditingStrategy>(position);
 }
 
 Position nextVisuallyDistinctCandidate(const Position& position)
 {
+    // FIXME: Use PositionIterator instead.

[leviw_travelin_and_unemployed, 2015/06/25 00:15:20]

We use TODO(name) syntax in Blink now.

[changseok, 2015/06/25 03:49:39]

Done.

     Position p = position;
     Position downstreamStart = p.downstream();
     while (!p.atEndOfTree()) {
         p = p.next(Character);
         if (p.isCandidate() && p.downstream() != downstreamStart)
             return p;
+        if (auto* node = p.containerNode()) {
+            if (!node->layoutObject())
+                p = lastPositionInOrAfterNode(node);
+        }
     }
     return Position();
 }
 
 template <typename Strategy>
 typename Strategy::PositionType previousCandidateAlgorithm(const typename Strategy::PositionType& position)
 {
     using PositionType = typename Strategy::PositionType;
     typename Strategy::PositionIteratorType p(position);
     while (!p.atStart()) {
         p.decrement();
         if (p.isCandidate())
             return p;
     }
     return PositionType();
 }
 
 Position previousCandidate(const Position& position)
 {
     return previousCandidateAlgorithm<EditingStrategy>(position);
 }
 
 template <typename PositionType>
 PositionType previousVisuallyDistinctCandidateAlgorithm(const PositionType& position)
 {
+    // FIXME: Use PositionIterator instead.
     PositionType p = position;
     PositionType downstreamStart = p.downstream();
     while (!p.atStartOfTree()) {
         p = p.previous(Character);
         if (p.isCandidate() && p.downstream() != downstreamStart)
             return p;
+        if (auto* node = p.containerNode()) {
+            if (!node->layoutObject())
+                p = firstPositionInOrBeforeNode(node);
+        }
     }
     return PositionType();
 }
 
 Position previousVisuallyDistinctCandidate(const Position& position)
 {
     return previousVisuallyDistinctCandidateAlgorithm<Position>(position);
 }
 
 VisiblePosition firstEditableVisiblePositionAfterPositionInRoot(const Position& position, ContainerNode* highestRoot)
@@ skipping 928 matching lines @@
     // if the selection starts just before a paragraph break, skip over it
     if (isEndOfParagraph(visiblePosition))
         return visiblePosition.next().deepEquivalent().downstream();
 
     // otherwise, make sure to be at the start of the first selected node,
     // instead of possibly at the end of the last node before the selection
     return visiblePosition.deepEquivalent().downstream();
 }
 
 } // namespace blink