[DMC #4] Add CompositionMarkerListImpl

third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp

 // 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.
 
 #include "core/editing/markers/GenericDocumentMarkerListImpl.h"
 
 #include "core/editing/markers/DocumentMarkerListEditor.h"
 #include "core/editing/markers/RenderedDocumentMarker.h"
 
 namespace blink {
 
 bool GenericDocumentMarkerListImpl::IsEmpty() const {
   return markers_.IsEmpty();
 }
 
 void GenericDocumentMarkerListImpl::Add(DocumentMarker* marker) {
   switch (marker->GetType()) {
     case DocumentMarker::kSpelling:
     case DocumentMarker::kGrammar:
       DocumentMarkerListEditor::AddMarkerAndMergeOverlapping(&markers_, marker);
       return;
     case DocumentMarker::kTextMatch:
-    case DocumentMarker::kComposition:
       DocumentMarkerListEditor::AddMarkerWithoutMergingOverlapping(&markers_,
                                                                    marker);
       return;
+    case DocumentMarker::kComposition:
+      NOTREACHED();
   }
 
   NOTREACHED();
   return;
 }
 
 void GenericDocumentMarkerListImpl::Clear() {
   markers_.clear();
 }
 
@@ skipping 26 matching lines @@
   return DocumentMarkerListEditor::ShiftMarkers(&markers_, offset, old_length,
                                                 new_length);
 }
 
 DEFINE_TRACE(GenericDocumentMarkerListImpl) {
   visitor->Trace(markers_);
   DocumentMarkerList::Trace(visitor);
 }
 
 }  // namespace blink