[Chrome OS Tether] Create BleAdvertisementDeviceQueue.

chromeos/components/tether/BUILD.gn

 # Copyright 2016 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.
 
 assert(is_chromeos, "Non-ChromeOS builds cannot depend on //chromeos")
 
 static_library("tether") {
   sources = [
+    "ble_advertisement_device_queue.cc",
+    "ble_advertisement_device_queue.h",
     "initializer.cc",
     "initializer.h",
   ]
 
   deps = [
     "//base",
   ]
 }
 
 static_library("test_support") {
   testonly = true
 
   sources = []
 
   public_deps = [
     ":tether",
   ]
 
   deps = [
     "//base",
     "//testing/gmock",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
 
-  sources = []
+  sources = [
+    "ble_advertisement_device_queue_unittest.cc",
+  ]
 
   deps = [
     ":test_support",
     ":tether",
     "//base/test:test_support",
+    "//components/cryptauth:test_support",
+    "//testing/gmock",
     "//testing/gtest",
   ]
 }