sky-scrollable should use a reasonable fling curve

sky/engine/core/events/GestureEvent.cpp

 // 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.
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/events/GestureEvent.h"
 #include "sky/engine/wtf/text/AtomicString.h"
 
 namespace blink {
@@ skipping 56 matching lines @@
 
 GestureEvent::GestureEvent(const WebGestureEvent& event)
     : Event(stringForType(event.type), true, true)
     , m_x(event.x)
     , m_y(event.y)
     , m_dx(0)
     , m_dy(0)
     , m_velocityX(0)
     , m_velocityY(0)
 {
+    m_timeStamp = event.timeStampMS;
+
     if (event.type == WebInputEvent::GestureFlingStart) {
         m_velocityX = event.data.flingStart.velocityX;
         m_velocityY = event.data.flingStart.velocityY;
     } else if (event.type == WebInputEvent::GestureScrollUpdate
             || event.type == WebInputEvent::GestureScrollUpdateWithoutPropagation) {
         m_dx = event.data.scrollUpdate.deltaX;
         m_dy = event.data.scrollUpdate.deltaY;
         m_velocityX = event.data.scrollUpdate.velocityX;
         m_velocityY = event.data.scrollUpdate.velocityY;
     }
 }
 
 GestureEvent::GestureEvent(const AtomicString& type, const GestureEventInit& initializer)
     : Event(type, initializer)
     , m_x(initializer.x)
     , m_y(initializer.y)
     , m_dx(initializer.dx)
     , m_dy(initializer.dy)
     , m_velocityX(initializer.velocityX)
     , m_velocityY(initializer.velocityY)
 {
 }
 
 } // namespace blink