Bug 164860 depends on one open bug:

•    164860: JS Modules in Workers [RESOLVED FIXED; assigned to ysuzuki]
  •    164425: Worker Script Loads (new Worker(...), importScripts(...)) should be classified as Scripts not Raw requests [NEW; assigned to ysuzuki]

Bug 164860 blocks one open bug:

•    164860: JS Modules in Workers [RESOLVED FIXED; assigned to ysuzuki]
  •    147340: [ES6] Implement ES6 Modules [NEW; assigned to ysuzuki]