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

ui/events/gestures/gesture_recognizer_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_
 #define UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 20 matching lines @@
 class EVENTS_EXPORT GestureRecognizerImpl : public GestureRecognizer,
                                             public GestureProviderAuraClient {
  public:
   typedef std::map<int, GestureConsumer*> TouchIdToConsumerMap;
 
   GestureRecognizerImpl();
   ~GestureRecognizerImpl() override;
 
   std::vector<GestureEventHelper*>& helpers() { return helpers_; }
 
+  // Returns a list of events of type |type|, one for each pointer down on
+  // |consumer|. Event locations are pulled from the active pointers.
+  std::vector<std::unique_ptr<TouchEvent>> GetEventPerPointForConsumer(
+      GestureConsumer* consumer,
+      EventType type);
+
   // Overridden from GestureRecognizer
   GestureConsumer* GetTouchLockedTarget(const TouchEvent& event) override;
   GestureConsumer* GetTargetForLocation(const gfx::PointF& location,
                                         int source_device_id) override;
   void CancelActiveTouchesExcept(GestureConsumer* not_cancelled) override;
   void TransferEventsTo(GestureConsumer* current_consumer,
-                        GestureConsumer* new_consumer) override;
+                        GestureConsumer* new_consumer,
+                        ShouldCancelTouches should_cancel_touches) override;
   bool GetLastTouchPointForTarget(GestureConsumer* consumer,
                                   gfx::PointF* point) override;
   bool CancelActiveTouches(GestureConsumer* consumer) override;
 
  protected:
   virtual GestureProviderAura* GetGestureProviderForConsumer(
       GestureConsumer* c);
 
  private:
   // Sets up the target consumer for gestures based on the touch-event.
@@ skipping 33 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(GestureRecognizerImpl);
 };
 
 // Provided only for testing:
 EVENTS_EXPORT void SetGestureRecognizerForTesting(
     GestureRecognizer* gesture_recognizer);
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_GESTURES_GESTURE_RECOGNIZER_IMPL_H_