DevTools: add "Jump to Relayout Boundary" context menu item in Elements panel

Source/devtools/front_end/DOMAgent.js

 /*
  * Copyright (C) 2009, 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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 586 matching lines @@
      * @param {WebInspector.DOMNode} targetNode
      * @param {?WebInspector.DOMNode} anchorNode
      * @param {function(?Protocol.Error, DOMAgent.NodeId=)=} callback
      */
     moveTo: function(targetNode, anchorNode, callback)
     {
         DOMAgent.moveTo(this.id, targetNode.id, anchorNode ? anchorNode.id : undefined, WebInspector.domAgent._markRevision(this, callback));
     },
 
     /**
+     * @param {function(?Protocol.Error, DOMAgent.NodeId=)} callback
+     */
+    findRelayoutBoundary: function(callback)
+    {
+        DOMAgent.relayoutBoundaryForNode(this.id, callback);
+    },
+
+    /**
      * @return {boolean}
      */
     isXMLNode: function()
     {
         return !!this.ownerDocument && !!this.ownerDocument.xmlVersion;
     },
 
     /**
      * @param {boolean} optimized
      * @return {string}
@@ skipping 939 matching lines @@
     shadowRootPopped: function(hostId, rootId)
     {
         this._domAgent._shadowRootPopped(hostId, rootId);
     }
 }
 
 /**
  * @type {?WebInspector.DOMAgent}
  */
 WebInspector.domAgent = null;