Add DiscoveryNetworkMonitor implementation

chrome/browser/extensions/api/dial/dial_api.cc

 // Copyright (c) 2012 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/extensions/api/dial/dial_api.h"
 
 #include <stddef.h>
 #include <utility>
 #include <vector>
 
@@ skipping 243 matching lines @@
 
 void DialFetchDeviceDescriptionFunction::OnFetchError(
     const std::string& message) {
   // Destroy the DeviceDescriptionFetcher since it still contains a reference
   // to |this| in its un-invoked callback.
   device_description_fetcher_.reset();
   SetError(message);
   SendResponse(false);
 }
 
+DialGetNetworkIdFunction::DialGetNetworkIdFunction() {}
+
+DialGetNetworkIdFunction::~DialGetNetworkIdFunction() {}
+
+bool DialGetNetworkIdFunction::RunAsync() {
+  auto* network_monitor = DiscoveryNetworkMonitor::GetInstance();
+  // If we are the first to call the DiscoveryNetworkMonitor, it will have no
+  // network state.  Force a refresh to be sure the network ID is populated.
+  network_monitor->ForceNetworkInfoRefresh(
+      base::Bind(&DialGetNetworkIdFunction::NetworkIdCallback, this));
+  return true;
+}
+
+void DialGetNetworkIdFunction::NetworkIdCallback() {
+  const auto* network_monitor = DiscoveryNetworkMonitor::GetInstance();
+  std::string network_id(network_monitor->GetNetworkId());
+  if (network_id.size() == 0) {
+    SetResult(base::MakeUnique<base::Value>(std::string("unknown")));
+    SendResponse(true);
+    return;
+  }
+  SetResult(base::MakeUnique<base::Value>(network_id));
+  SendResponse(true);
+}
+
 }  // namespace extensions