exo: Replace fling cancel with generic zero distance scroll

components/exo/pointer_delegate.h

 // Copyright 2015 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 COMPONENTS_EXO_POINTER_DELEGATE_H_
 #define COMPONENTS_EXO_POINTER_DELEGATE_H_
 
 #include "base/time/time.h"
 #include "ui/events/event_constants.h"
 
@@ skipping 39 matching lines @@
                                int changed_button_flags,
                                bool pressed) = 0;
 
   // Called when pointer is scrolling. |offset| contains the direction and
   // distance of the change. |discrete| is true if the scrolling is caused
   // by a discrete device such as a scroll wheel.
   virtual void OnPointerScroll(base::TimeTicks time_stamp,
                                const gfx::Vector2dF& offset,
                                bool discrete) = 0;
 
-  // Called when a current kinetic scroll should be canceled.
-  virtual void OnPointerScrollCancel(base::TimeTicks time_stamp) = 0;
-
   // Called when pointer scroll has stopped and a fling is happening (e.g.
   // lifting the fingers from the touchpad after scrolling quickly)
   virtual void OnPointerScrollStop(base::TimeTicks time_stamp) = 0;
 
   // Called after all pointer information of this frame has been set and the
   // client should evaluate the updated state. No events are being sent before
   // this method is called.
   virtual void OnPointerFrame() = 0;
 
  protected:
   virtual ~PointerDelegate() {}
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_POINTER_DELEGATE_H_