Add tests for DocumentMarkerListEditor::ShiftMarkersContent{D,Ind}ependent

third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.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 DocumentMarkerListEditor_h
 #define DocumentMarkerListEditor_h
 
 #include "core/editing/markers/DocumentMarkerList.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class DocumentMarker;
 
-class DocumentMarkerListEditor {
+class CORE_EXPORT DocumentMarkerListEditor final {
  public:
   using MarkerList = HeapVector<Member<DocumentMarker>>;
 
   static void AddMarkerWithoutMergingOverlapping(MarkerList*, DocumentMarker*);
 
   // Returns true if a marker was moved, false otherwise.
   static bool MoveMarkers(MarkerList* src_list,
                           int length,
                           DocumentMarkerList* dst_list);
 
@@ skipping 17 matching lines @@
   // Returns true if a marker was shifted or removed, false otherwise.
   static bool ShiftMarkersContentIndependent(MarkerList*,
                                              unsigned offset,
                                              unsigned old_length,
                                              unsigned new_length);
 };
 
 }  // namespace blink
 
 #endif  // DocumentMarkerListEditor_h