Add CompositionMarkerList in preparation for DocumentMarkerController refactor

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.h
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.h b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.h
index 7d56b8a499759acaa533cd738a4fb483e50e3220..d68681b191819b80a8ea6beca0da9e33bb88b949 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.h
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.h
@@ -63,6 +63,7 @@ class CORE_EXPORT DocumentMarkerController final
   explicit DocumentMarkerController(Document&);
 
   void clear();
+  void addMarker(Node*, const DocumentMarker&);
   void addMarker(const Position& start,
                  const Position& end,
                  DocumentMarker::MarkerType,
@@ -139,8 +140,6 @@ class CORE_EXPORT DocumentMarkerController final
                               unsigned newLength) final;
 
  private:
-  void addMarker(Node*, const DocumentMarker&);
-
   using MarkerList = HeapVector<Member<RenderedDocumentMarker>>;
   using MarkerLists =
       HeapVector<Member<MarkerList>, DocumentMarker::MarkerTypeIndexesCount>;