Report accurate Overscroll on handleWheel.

Source/platform/scroll/ScrollableArea.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  * Copyright (C) 2008, 2011 Apple 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.
@@ skipping 283 matching lines @@
     else
         return false;
 
     return true;
 }
 
 ScrollResult ScrollableArea::handleWheel(const PlatformWheelEvent& wheelEvent)
 {
     // Wheel events which do not scroll are used to trigger zooming.
     if (!wheelEvent.canScroll())
-        return ScrollResult();
+        return ScrollResult(false, false, wheelEvent.deltaX(), wheelEvent.deltaY());

[bokan, 2015/06/23 16:20:45]

Doesn't this mean that a browser zoom (ctrl + wheel) will now trigger
overscroll?

[MuVen, 2015/06/25 12:55:51]

Done. True, i checked it, it wont trigger overscroll. Thanks for pointing out.

 
     cancelProgrammaticScrollAnimation();
     return scrollAnimator()->handleWheelEvent(wheelEvent);
 }
 
 IntPoint ScrollableArea::adjustScrollPositionWithinRange(const IntPoint& scrollPoint) const
 {
     if (!constrainsScrollingToContentEdge())
         return scrollPoint;
 
@@ skipping 307 matching lines @@
         verticalScrollbarWidth = !verticalBar->isOverlayScrollbar() ? verticalBar->width() : 0;
     if (Scrollbar* horizontalBar = horizontalScrollbar())
         horizontalScrollbarHeight = !horizontalBar->isOverlayScrollbar() ? horizontalBar->height() : 0;
 
     return IntSize(std::max(0, size.width() - verticalScrollbarWidth),
         std::max(0, size.height() - horizontalScrollbarHeight));
 
 }
 
 } // namespace blink