[Editing] Store |CommandSource| in |CompositeEditCommand|

third_party/WebKit/Source/core/page/DragController.cpp

Index: third_party/WebKit/Source/core/page/DragController.cpp
diff --git a/third_party/WebKit/Source/core/page/DragController.cpp b/third_party/WebKit/Source/core/page/DragController.cpp
index 8a439f75018f8ab3745ac250cef85eef87e3e3f3..1468b7a9671b66bf600cec083969cd6976503fa4 100644
--- a/third_party/WebKit/Source/core/page/DragController.cpp
+++ b/third_party/WebKit/Source/core/page/DragController.cpp
@@ -581,8 +581,8 @@ bool DragController::concludeEditDrag(DragData* dragData) {
 
   // Start new Drag&Drop command group, invalidate previous command group.
   // Assume no other places is firing |DeleteByDrag| and |InsertFromDrop|.
-  innerFrame->editor().registerCommandGroup(
-      DragAndDropCommand::create(*innerFrame->document()));
+  innerFrame->editor().registerCommandGroup(DragAndDropCommand::create(
+      *innerFrame->document(), CommandSource::MenuOrKeyBinding));
 
   if (dragIsMove(innerFrame->selection(), dragData) ||
       dragCaret.isContentRichlyEditable()) {