code: void updateAfterDeserialize(Node jsRoot) {
      // TODO(bradfordcsmith): Restore line counts for inputs and externs.
      this.jsRoot = jsRoot;
      if (!tracksAstSize()) {
        return;
      }
      this.initAstSize = this.astSize = NodeUtil.countAstSize(this.jsRoot);
      if (!tracksSize()) {
        return;
      }
      PerformanceTrackerCodeSizeEstimator estimator =
          PerformanceTrackerCodeSizeEstimator.estimate(this.jsRoot, tracksGzSize());
      this.initCodeSize = this.codeSize = estimator.getCodeSize();
      if (tracksGzSize()) {
        this.initGzCodeSize = this.gzCodeSize = estimator.getZippedCodeSize();
      }
    }
docs: Updates the saved jsRoot and resets the size tracking fields accordingly.
  @param jsRoot