Move JS support code from //mojo/edk/js to //services/js/system

services/js/modules/clock/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 source_set("clock") {
   sources = [
     "monotonic_clock.cc",
     "monotonic_clock.h",
   ]
 
   deps = [
     "//base",
     "//gin",
-    "//mojo/edk/js",
     "//mojo/public/cpp/system",
+    "//services/js/system",
     "//v8",
   ]
 }