Indicate whether a touch event will cause scrolling

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 <map>
 #include <vector>
 
@@ skipping 39 matching lines @@
   virtual GestureProviderAura* GetGestureProviderForConsumer(
       GestureConsumer* c);
 
  private:
   // Sets up the target consumer for gestures based on the touch-event.
   void SetupTargets(const TouchEvent& event, GestureConsumer* consumer);
 
   void DispatchGestureEvent(GestureEvent* event);
 
   // Overridden from GestureRecognizer
-  bool ProcessTouchEventPreDispatch(const TouchEvent& event,
+  bool ProcessTouchEventPreDispatch(TouchEvent* event,
                                     GestureConsumer* consumer) override;
 
   Gestures* ProcessTouchEventPostDispatch(const TouchEvent& event,
                                           ui::EventResult result,
                                           GestureConsumer* consumer) override;
 
   Gestures* ProcessTouchEventOnAsyncAck(const TouchEvent& event,
                                         ui::EventResult result,
                                         GestureConsumer* consumer) override;
 
@@ skipping 21 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_