Drag and drop cleans up touch sequences from the source window.

ash/drag_drop/drag_drop_controller.cc

Index: ash/drag_drop/drag_drop_controller.cc
diff --git a/ash/drag_drop/drag_drop_controller.cc b/ash/drag_drop/drag_drop_controller.cc
index 338bb7baadbcaca3fd6f84eb6d81c3e97b912cc9..b8001e60b81df43e043e05a8289b274b2a890813 100644
--- a/ash/drag_drop/drag_drop_controller.cc
+++ b/ash/drag_drop/drag_drop_controller.cc
@@ -173,8 +173,9 @@ int DragDropController::StartDragAndDrop(
     // We need to transfer the current gesture sequence and the GR's touch event
     // queue to the |drag_drop_tracker_|'s capture window so that when it takes
     // capture, it still gets a valid gesture state.
-    ui::GestureRecognizer::Get()->TransferEventsTo(source_window,
-        tracker->capture_window());
+    ui::GestureRecognizer::Get()->TransferEventsTo(
+        source_window, tracker->capture_window(),
+        ui::GestureRecognizer::ShouldCancelTouches::Cancel);
     // We also send a gesture end to the source window so it can clear state.
     // TODO(varunjain): Remove this whole block when gesture sequence
     // transferring is properly done in the GR (http://crbug.com/160558)