Implement top controls show/hide functionality for main thread scrolling

Source/web/WebInputEventConversion.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 271 matching lines @@
         break;
     default:
         ASSERT_NOT_REACHED();
     }
     m_position = widget->convertFromContainingWindow(flooredIntPoint(convertHitPointToWindow(widget, FloatPoint(e.x, e.y))));
     m_globalPosition = IntPoint(e.globalX, e.globalY);
     m_timestamp = e.timeStampSeconds;
     m_modifiers = toPlatformEventModifiers(e.modifiers);
 }
 
+
+PlatformGestureEventBuilder::PlatformGestureEventBuilder(Widget* widget, const WebGestureEvent& e, float deltaX, float deltaY)
+    : PlatformGestureEventBuilder(widget, e)
+{
+    if (m_type == PlatformEvent::GestureScrollUpdate) {
+        m_data.m_scrollUpdate.m_deltaX = deltaX;
+        m_data.m_scrollUpdate.m_deltaY = deltaY;
+    }
+}
+
+
 // MakePlatformKeyboardEvent --------------------------------------------------
 
 inline PlatformEvent::Type toPlatformKeyboardEventType(WebInputEvent::Type type)
 {
     switch (type) {
     case WebInputEvent::KeyUp:
         return PlatformEvent::KeyUp;
     case WebInputEvent::KeyDown:
         return PlatformEvent::KeyDown;
     case WebInputEvent::RawKeyDown:
@@ skipping 506 matching lines @@
     modifiers = getWebInputModifiers(event);
 
     globalX = event.screenX();
     globalY = event.screenY();
     IntPoint localPoint = convertAbsoluteLocationForLayoutObject(event.absoluteLocation(), *layoutObject);
     x = localPoint.x();
     y = localPoint.y();
 }
 
 } // namespace blink