[DMC #10] Add type cast for TextMatchMarkerListImpl

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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TextMatchMarkerListImpl_h
 #define TextMatchMarkerListImpl_h
 
 #include "core/editing/markers/DocumentMarkerList.h"
 
 namespace blink {
@@ skipping 21 matching lines @@
                     unsigned old_length,
                     unsigned new_length) final;
   DECLARE_VIRTUAL_TRACE();
 
  private:
   HeapVector<Member<DocumentMarker>> markers_;
 
   DISALLOW_COPY_AND_ASSIGN(TextMatchMarkerListImpl);
 };
 
+DEFINE_TYPE_CASTS(TextMatchMarkerListImpl,
+                  DocumentMarkerList,
+                  list,
+                  list->MarkerType() == DocumentMarker::kTextMatch,
+                  list.MarkerType() == DocumentMarker::kTextMatch);
+
 }  // namespace blink
 
 #endif  // TextMatchMarkerListImpl_h