Convert main-thread overscroll parameters into viewport space.

third_party/WebKit/Source/core/input/EventHandler.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010, 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 289 matching lines @@
     // Returns true if the scroll was consumed.
     // direction - The logical direction to scroll in. This will be converted to
     //             a physical direction for each LayoutBox we try to scroll
     //             based on that box's writing mode.
     // granularity - The units that the  scroll delta parameter is in.
     // startNode - Optional. If provided, start chaining from the given node.
     //             If not, use the current focus or last clicked node.
     bool logicalScroll(ScrollDirection, ScrollGranularity, Node* startNode = nullptr);
 
     void resetOverscroll(bool didScrollX, bool didScrollY);
-    void handleOverscroll(const ScrollResult&, const FloatPoint& position = FloatPoint(), const FloatSize& velocity = FloatSize());
+    void handleOverscroll(const ScrollResult&, const FloatPoint& positionInRootFrame = FloatPoint(), const FloatSize& velocity = FloatSize());
 
     void customizedScroll(const Node& startNode, ScrollState&);
 
     HitTestResult hitTestResultInFrame(LocalFrame*, const LayoutPoint&, HitTestRequest::HitTestRequestType hitType = HitTestRequest::ReadOnly | HitTestRequest::Active);
 
     void invalidateClick();
 
     Node* updateMouseEventTargetNode(Node*, const PlatformMouseEvent&);
     void updateMouseEventTargetNodeAndSendEvents(Node*, const PlatformMouseEvent&, bool isFrameBoundaryTransition = false);
 
@@ skipping 167 matching lines @@
     // scroll which shouldn't propagate can't cause any element to
     // scroll other than the |m_previousGestureScrolledNode|.
     bool m_deltaConsumedForScrollSequence;
 };
 
 } // namespace blink
 
 WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(blink::EventHandler::TouchInfo);
 
 #endif // EventHandler_h