Fix dragging text inside a input element nested in a draggable element.

Source/core/page/DragController.h

 /*
  * Copyright (C) 2007, 2009 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 45 matching lines @@
     public:
         ~DragController();
 
         static PassOwnPtr<DragController> create(Page*, DragClient*);
 
         DragSession dragEntered(DragData*);
         void dragExited(DragData*);
         DragSession dragUpdated(DragData*);
         bool performDrag(DragData*);
 
-        Node* draggableNode(const Frame*, Node*, const IntPoint&, DragState&) const;
+        enum SelectionDragPolicy {
+            ImmediateSelectionDragResolution,
+            DelayedSelectionDragResolution,
+        };
+        Node* draggableNode(const Frame*, Node*, const IntPoint&, SelectionDragPolicy, DragSourceAction&) const;
         void dragEnded();
 
         bool populateDragClipboard(Frame* src, const DragState&, const IntPoint& dragOrigin);
         bool startDrag(Frame* src, const DragState&, const PlatformMouseEvent& dragEvent, const IntPoint& dragOrigin);
 
         static const int DragIconRightInset;
         static const int DragIconBottomInset;
 
     private:
         DragController(Page*, DragClient*);
@@ skipping 23 matching lines @@
         RefPtr<HTMLInputElement> m_fileInputElementUnderMouse;
         bool m_documentIsHandlingDrag;
 
         DragDestinationAction m_dragDestinationAction;
         bool m_didInitiateDrag;
     };
 
 }
 
 #endif