Revert of Preventing the default action on 'mousemove' listener shouldn't prevent selection

Source/core/page/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 1481 matching lines @@
             }
         }
     }
 
     m_lastMouseMoveEventSubframe = newSubframe;
 
     if (swallowEvent)
         return true;
 
     swallowEvent = !dispatchMouseEvent(EventTypeNames::mousemove, mev.innerNode(), 0, mouseEvent, true);
+    if (!swallowEvent)
+        swallowEvent = handleMouseDraggedEvent(mev);
 
-    // http://www.w3.org/TR/DOM-Level-3-Events/#event-type-mousemove
-    // Since there is no default action for the mousemove event issue a
-    // mouse dragged event irrespective of whether the event is cancelled.
-    return handleMouseDraggedEvent(mev);
+    return swallowEvent;
 }
 
 void EventHandler::invalidateClick()
 {
     m_clickCount = 0;
     m_clickNode = nullptr;
 }
 
 static ContainerNode* parentForClickEvent(const Node& node)
 {
@@ skipping 2433 matching lines @@
 
     // If it's in the direction to hide the top controls, only consume when the frame can also scroll.
     if (m_frame->view()->scrollPosition().y() < m_frame->view()->maximumScrollPosition().y())
         return true;
 
     return false;
 }
 
 
 } // namespace blink