Fix draggable elements are painted at incorrect position

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  *
  * 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.
@@ skipping 669 matching lines @@
         return false;
     // FIXME: Broken for OOPI.
     return toLocalFrame(parentFrame)->eventHandler().bubblingScroll(direction, granularity, m_frame->deprecatedLocalOwner());
 }
 
 IntPoint EventHandler::lastKnownMousePosition() const
 {
     return m_lastKnownMousePosition;
 }
 
+IntPoint EventHandler::dragDataTransferLocationForTesting()
+{
+    if (dragState().m_dragDataTransfer)
+        return dragState().m_dragDataTransfer->dragLocation();
+
+    return IntPoint();
+}
+
 static LocalFrame* subframeForTargetNode(Node* node)
 {
     if (!node)
         return nullptr;
 
     LayoutObject* layoutObject = node->layoutObject();
     if (!layoutObject || !layoutObject->isLayoutPart())
         return nullptr;
 
     Widget* widget = toLayoutPart(layoutObject)->widget();
@@ skipping 2614 matching lines @@
     // The DataTransfer would only be non-empty if we missed a dragEnd.
     // Clear it anyway, just to make sure it gets numbified.
     clearDragDataTransfer();
 
     dragState().m_dragDataTransfer = createDraggingDataTransfer();
 
     // Check to see if this a DOM based drag, if it is get the DOM specified drag
     // image and offset
     if (dragState().m_dragType == DragSourceActionDHTML) {
         if (LayoutObject* layoutObject = dragState().m_dragSrc->layoutObject()) {
-            FloatPoint absPos = layoutObject->localToAbsolute(FloatPoint(), UseTransforms);
-            IntSize delta = m_mouseDownPos - roundedIntPoint(absPos);
+            IntRect absoluteBoundingBox = layoutObject->absoluteBoundingBoxRect();

[fs, 2016/02/24 12:51:16]

Why did you switch this to absoluteBoundingBoxRect (from
absoluteBoundingBoxRectIncludingDescendants)?

[hyunjunekim2, 2016/02/24 13:06:36]

|absoluteBoundingBoxRect| function was thought to include both.
But re-change |absoluteBoundingBoxRectIncludingDescendants|.
Because |absoluteBoundingBoxRectIncludingDescendants| function contains
|absoluteBoundingBoxrect| Layer of children.

+            IntSize delta = m_mouseDownPos - absoluteBoundingBox.location();
             dragState().m_dragDataTransfer->setDragImageElement(dragState().m_dragSrc.get(), IntPoint(delta));
         } else {
             // The layoutObject has disappeared, this can happen if the onStartDrag handler has hidden
             // the element in some way. In this case we just kill the drag.
             return false;
         }
     }
 
     DragController& dragController = m_frame->page()->dragController();
     if (!dragController.populateDragDataTransfer(m_frame, dragState(), m_mouseDownPos))
@@ skipping 638 matching lines @@
 PlatformEvent::Modifiers EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return static_cast<PlatformEvent::Modifiers>(PlatformEvent::CtrlKey | PlatformEvent::AltKey);
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink