[DMC #23] Add CompositionMarker (subclass of DocumentMarker)

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
index 545678929d4ee0cb63895f7027c62bf4c52bd45e..0064a7f4c21f0ce6fef7e6cac1c1b8d8ad02e76b 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -34,6 +34,7 @@
 #include "core/dom/Text.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/iterators/TextIterator.h"
+#include "core/editing/markers/CompositionMarker.h"
 #include "core/editing/markers/CompositionMarkerListImpl.h"
 #include "core/editing/markers/DocumentMarkerListEditor.h"
 #include "core/editing/markers/GrammarMarkerListImpl.h"
@@ -162,8 +163,8 @@ void DocumentMarkerController::AddCompositionMarker(const EphemeralRange& range,
   DCHECK(!document_->NeedsLayoutTreeUpdate());
   AddMarkerInternal(range, [underline_color, thick, background_color](
                                int start_offset, int end_offset) {
-    return new DocumentMarker(start_offset, end_offset, underline_color, thick,
-                              background_color);
+    return new CompositionMarker(start_offset, end_offset, underline_color,
+                                 thick, background_color);
   });
 }