DevTools: Treat system object distances with less priority

Source/devtools/front_end/HeapSnapshot.js

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1311 matching lines @@
                 return;
             distances[ordinal] = distance;
             nodesToVisit[nodesToVisitLength++] = node.nodeIndex;
         }
 
         this.forEachRoot(enqueueNode.bind(null, 1), true);
         this._bfs(nodesToVisit, nodesToVisitLength, distances);
 
         // bfs for the rest of objects
         nodesToVisitLength = 0;
-        this.forEachRoot(enqueueNode.bind(null, 0), false);
+        this.forEachRoot(enqueueNode.bind(null, WebInspector.HeapSnapshotCommon.baseSystemDistance), false);
         this._bfs(nodesToVisit, nodesToVisitLength, distances);
     },
 
     /**
      * @param {!Uint32Array} nodesToVisit
      * @param {!number} nodesToVisitLength
      * @param {!Int32Array} distances
      */
     _bfs: function(nodesToVisit, nodesToVisitLength, distances)
     {
@@ skipping 968 matching lines @@
      * @param {number} windowRight
      */
     sort: function(comparator, leftBound, rightBound, windowLeft, windowRight)
     {
         this._iterationOrder.sortRange(this._buildCompareFunction(comparator), leftBound, rightBound, windowLeft, windowRight);
     },
 
     __proto__: WebInspector.HeapSnapshotItemProvider.prototype
 }