[DMC #24] Add SpellingMarker and GrammarMarker (subclasses of DocumentMarker)

third_party/WebKit/Source/core/testing/Internals.cpp

Index: third_party/WebKit/Source/core/testing/Internals.cpp
diff --git a/third_party/WebKit/Source/core/testing/Internals.cpp b/third_party/WebKit/Source/core/testing/Internals.cpp
index cdc6f2a23b7d8894c1a4cf2a9d0ff1f9b24bc404..6829be1f8447ec9f0b27c28584da1f167635c161 100644
--- a/third_party/WebKit/Source/core/testing/Internals.cpp
+++ b/third_party/WebKit/Source/core/testing/Internals.cpp
@@ -65,6 +65,7 @@
 #include "core/editing/iterators/TextIterator.h"
 #include "core/editing/markers/DocumentMarker.h"
 #include "core/editing/markers/DocumentMarkerController.h"
+#include "core/editing/markers/SpellCheckMarker.h"
 #include "core/editing/markers/TextMatchMarker.h"
 #include "core/editing/serializers/Serialization.h"
 #include "core/editing/spellcheck/IdleSpellCheckCallback.h"
@@ -1010,9 +1011,9 @@ String Internals::markerDescriptionForNode(Node* node,
                                            unsigned index,
                                            ExceptionState& exception_state) {
   DocumentMarker* marker = MarkerAt(node, marker_type, index, exception_state);
-  if (!marker)
+  if (!marker || !IsSpellCheckMarker(*marker))
     return String();
-  return marker->Description();
+  return ToSpellCheckMarker(marker)->Description();
 }
 
 static WTF::Optional<TextMatchMarker::MatchStatus> MatchStatusFrom(