[DMC #5] Add SpellCheckMarkerListImpl

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 dc2881b92fbe6d4cfae34626bc7e712bcfb6ae0e..fd968340551a8341c67add0f4a9d59226d5de47a 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -38,6 +38,7 @@
 #include "core/editing/markers/DocumentMarkerListEditor.h"
 #include "core/editing/markers/GenericDocumentMarkerListImpl.h"
 #include "core/editing/markers/RenderedDocumentMarker.h"
+#include "core/editing/markers/SpellCheckMarkerListImpl.h"
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutObject.h"
 
@@ -70,6 +71,9 @@ DocumentMarkerList* CreateListForType(DocumentMarker::MarkerType type) {
   switch (type) {
     case DocumentMarker::kComposition:
       return new CompositionMarkerListImpl();
+    case DocumentMarker::kSpelling:
+    case DocumentMarker::kGrammar:
+      return new SpellCheckMarkerListImpl();
     default:
       return new GenericDocumentMarkerListImpl();
   }
@@ -512,7 +516,8 @@ void DocumentMarkerController::RemoveSpellingMarkersUnderWords(
       DocumentMarkerList* const list = ListForType(markers, type);
       if (!list)
         continue;
-      list->RemoveMarkersUnderWords(ToText(node).data(), words);
+      static_cast<SpellCheckMarkerListImpl* const>(list)

[yosin_UTC9, 2017/05/08 04:50:54]

nit: s/ const//

We should use DEFINE_TYPE_CAST(), in "wtf/Assertion.h" for downcasting.

See Document.h for small example:
DEFINE_TYPE_CASTS(Document,
                  ExecutionContext,
                  context,
                  context->IsDocument(),

+          ->RemoveMarkersUnderWords(ToText(node).data(), words);
     }
   }
 }