code: function(profileDataGridNode)
      {
          if (!profileDataGridNode)
              return;
  
          this.save();
  
          var currentNode = profileDataGridNode;
          var focusNode = profileDataGridNode;
  
          while (currentNode.parent && (currentNode instanceof WebInspector.ProfileDataGridNode)) {
              currentNode._takePropertiesFromProfileDataGridNode(profileDataGridNode);
  
              focusNode = currentNode;
              currentNode = currentNode.parent;
  
              if (currentNode instanceof WebInspector.ProfileDataGridNode)
                  currentNode._keepOnlyChild(focusNode);
          }
  
          this.children = [focusNode];
          this.totalTime = profileDataGridNode.totalTime;
      }
docs: When focusing, we keep the entire callstack up to this ancestor.
  @param {!WebInspector.ProfileDataGridNode} profileDataGridNode