Method constructor

deps/v8/tools/profview/profile-utils.js:246–251

(filter, isBottomUp)

class PlainCallTreeProcessor {
  constructor(filter, isBottomUp) {
    this.filter = filter;
    this.tree = createEmptyNode("root");
    this.tree.delayedExpansion = { frameList : [], ascending : isBottomUp };
    this.isBottomUp = isBottomUp;
  }

  addStack(file, tickIndex) {
    let stack = file.ticks[tickIndex].s;