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

ui/events/gestures/gesture_provider_aura.cc

Index: ui/events/gestures/gesture_provider_aura.cc
diff --git a/ui/events/gestures/gesture_provider_aura.cc b/ui/events/gestures/gesture_provider_aura.cc
index 3d0e9da50b28bbaad761bb809f03494d4325f417..739d1df0677e3ad58028ba59254a036f60b115e6 100644
--- a/ui/events/gestures/gesture_provider_aura.cc
+++ b/ui/events/gestures/gesture_provider_aura.cc
@@ -9,6 +9,7 @@
 #include "base/auto_reset.h"
 #include "base/logging.h"
 #include "ui/events/event.h"
+#include "ui/events/event_utils.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
 #include "ui/events/gesture_detection/gesture_event_data.h"
 #include "ui/events/gesture_detection/gesture_provider_config_helper.h"
@@ -74,4 +75,16 @@ ScopedVector<GestureEvent>* GestureProviderAura::GetAndResetPendingGestures() {
   return old_pending_gestures;
 }
 
+void GestureProviderAura::OnTouchEnter(int pointer_id, float x, float y) {
+  std::unique_ptr<TouchEvent> touch_event(new TouchEvent(
+      ET_TOUCH_PRESSED, gfx::Point(), EF_IS_SYNTHESIZED, pointer_id,
+      ui::EventTimeForNow(), 0.0f, 0.0f, 0.0f, 0.0f));
+  gfx::PointF point(x, y);
+  touch_event->set_location_f(point);
+  touch_event->set_root_location_f(point);
+
+  OnTouchEvent(touch_event.get());
+  OnTouchEventAck(touch_event->unique_event_id(), true);
+}
+
 }  // namespace content