Add DiscoveryNetworkMonitor implementation

chrome/browser/media/router/discovery/discovery_network_list_unittest.cc

+// Copyright (c) 2017 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.
+
+#include "chrome/browser/media/router/discovery/discovery_network_list.h"
+
+#include <algorithm>
+#include <iterator>
+#include <set>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(DiscoveryNetworkListTest, GetDiscoveryNetworkInfoList) {
+  auto network_ids = GetDiscoveryNetworkInfoList();
+  for (const auto& network_id : network_ids) {
+    // We can't mock out the OS layer used by GetDiscoveryNetworkIdList, so
+    // instead just check that each returned interface name is non-empty.
+    EXPECT_FALSE(network_id.name.empty());
+  }
+
+  // Also check that at most one ID is returned per interface name.
+  std::set<std::string> interface_name_set;
+  std::transform(begin(network_ids), end(network_ids),
+                 std::insert_iterator<std::set<std::string>>{
+                     interface_name_set, end(interface_name_set)},
+                 [](const DiscoveryNetworkInfo& network_info) {
+                   return network_info.name;
+                 });
+
+  EXPECT_EQ(interface_name_set.size(), network_ids.size());
+}
+
+TEST(DiscoveryNetworkListTest, StableSortDiscoveryNetworkInfoUnique) {
+  std::vector<DiscoveryNetworkInfo> network_info({
+      {"wlan0", "ssid0"}, {"wlan1", "ssid1"}, {"eth0", "de:ad:be:ef:00:11"},
+  });
+  std::vector<DiscoveryNetworkInfo> sorted_network_info({
+      {"eth0", "de:ad:be:ef:00:11"}, {"wlan0", "ssid0"}, {"wlan1", "ssid1"},
+  });
+
+  StableSortDiscoveryNetworkInfo(network_info.begin(), network_info.end());
+
+  EXPECT_EQ(sorted_network_info, network_info);
+}
+
+TEST(DiscoveryNetworkListTest, StableSortDiscoveryNetworkInfoDuplicates) {
+  std::vector<DiscoveryNetworkInfo> network_info({
+      {"wlan1", "ssid0"}, {"eth0", "de:ad:be:ef:00:11"}, {"wlan0", "ssid0"},
+  });
+  std::vector<DiscoveryNetworkInfo> sorted_network_info({
+      {"eth0", "de:ad:be:ef:00:11"}, {"wlan1", "ssid0"}, {"wlan0", "ssid0"},
+  });
+
+  StableSortDiscoveryNetworkInfo(network_info.begin(), network_info.end());
+
+  EXPECT_EQ(sorted_network_info, network_info);
+}