Add DocumentMarker::createCompositionMarker()

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 f6e419e2d5cbca207890593d2cea93cc87e599f9..5279f601b04bb6460a55fc12a351d2d1ba20bf3b 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerController.cpp
@@ -102,9 +102,10 @@ void DocumentMarkerController::addCompositionMarker(const Position& start,
   for (TextIterator markedText(start, end); !markedText.atEnd();
        markedText.advance()) {
     addMarker(markedText.currentContainer(),
-              new DocumentMarker(markedText.startOffsetInCurrentContainer(),
-                                 markedText.endOffsetInCurrentContainer(),
-                                 underlineColor, thick, backgroundColor));
+              DocumentMarker::createCompositionMarker(
+                  markedText.startOffsetInCurrentContainer(),
+                  markedText.endOffsetInCurrentContainer(), underlineColor,
+                  thick, backgroundColor));
   }
 }