[DMC #4] Add CompositionMarkerListImpl

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

Index: third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp b/third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp
index 5f0b66d71a7289b337e46ae6c2cb7203da3f3f19..bc83f4d1568c036d293a15a830e9fd0e4cd66693 100644
--- a/third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/GenericDocumentMarkerListImpl.cpp
@@ -20,10 +20,11 @@ void GenericDocumentMarkerListImpl::Add(DocumentMarker* marker) {
       DocumentMarkerListEditor::AddMarkerAndMergeOverlapping(&markers_, marker);
       return;
     case DocumentMarker::kTextMatch:
-    case DocumentMarker::kComposition:
       DocumentMarkerListEditor::AddMarkerWithoutMergingOverlapping(&markers_,
                                                                    marker);
       return;
+    case DocumentMarker::kComposition:
+      NOTREACHED();
   }
 
   NOTREACHED() << "Unhanded marker type: " << marker->GetType();