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

Source/core/editing/htmlediting.cpp

Index: Source/core/editing/htmlediting.cpp
diff --git a/Source/core/editing/htmlediting.cpp b/Source/core/editing/htmlediting.cpp
index 92908f769e5911808fa7392c593488c1fda0fcff..0995247eb5e0f4bff244c40a53dbc6684dc66ea6 100644
--- a/Source/core/editing/htmlediting.cpp
+++ b/Source/core/editing/htmlediting.cpp
@@ -230,12 +230,17 @@ Position nextCandidate(const Position& 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();
 }
@@ -261,12 +266,17 @@ Position previousCandidate(const Position& 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();
 }