lib/third_party/tracing/extras/rail/rail_ir_finder.js
function(lir) {
      var createChildEvent = undefined;
      lir.renderMainThread.iterateAllEvents(function(event) {
        if (event.title !== CREATE_CHILD_TITLE)
          return;

        if (event.args.child !== lir.routingId)
          return;

        createChildEvent = event;
      });

      if (!createChildEvent)
        return undefined;

      return createChildEvent.args.id;
    }
function(lir) {
      var createChildEvent = undefined;
      lir.renderMainThread.iterateAllEvents(function(event) {
        if (event.title !== CREATE_CHILD_TITLE)
          return;

        if (event.args.child !== lir.routingId)
          return;

        createChildEvent = event;
      });

      if (!createChildEvent)
        return undefined;

      return createChildEvent.args.id;
    }
function ( lir ) { var createChildEvent = undefined ; lir . renderMainThread . iterateAllEvents ( function ( event ) { if ( event . title !== CREATE_CHILD_TITLE ) return ; if ( event . args . child !== lir . routingId ) return ; createChildEvent = event ; } ) ; if ( ! createChildEvent ) return undefined ; return createChildEvent . args . id ; }
Find the routingId of the createChildFrame event that created the Load IR's RenderFrame.
Find the routingId of the createChildFrame event that created the Load IR s RenderFrame .