Migrate simple ash Shell metrics users.

ash/system/chromeos/network/tray_network.cc

Index: ash/system/chromeos/network/tray_network.cc
diff --git a/ash/system/chromeos/network/tray_network.cc b/ash/system/chromeos/network/tray_network.cc
index a8a290070255730d19532c8871ab4c5afed5a3c7..ff216adc05b0eccf0e923cc5f4270ae5a2b98e74 100644
--- a/ash/system/chromeos/network/tray_network.cc
+++ b/ash/system/chromeos/network/tray_network.cc
@@ -11,7 +11,7 @@
 #include "ash/common/system/tray/tray_item_more.h"
 #include "ash/common/system/tray/tray_item_view.h"
 #include "ash/common/system/tray/tray_utils.h"
-#include "ash/metrics/user_metrics_recorder.h"
+#include "ash/common/wm_shell.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/network/network_state_list_detailed_view.h"
@@ -273,8 +273,8 @@ views::View* TrayNetwork::CreateDefaultView(LoginStatus status) {
 
 views::View* TrayNetwork::CreateDetailedView(LoginStatus status) {
   CHECK(detailed_ == NULL);
-  Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-      ash::UMA_STATUS_AREA_DETAILED_NETWORK_VIEW);
+  WmShell::Get()->RecordUserMetricsAction(
+      UMA_STATUS_AREA_DETAILED_NETWORK_VIEW);
   if (!chromeos::NetworkHandler::IsInitialized())
     return NULL;
   if (request_wifi_view_) {
@@ -318,9 +318,8 @@ void TrayNetwork::RequestToggleWifi() {
   }
   NetworkStateHandler* handler = NetworkHandler::Get()->network_state_handler();
   bool enabled = handler->IsTechnologyEnabled(NetworkTypePattern::WiFi());
-  Shell::GetInstance()->metrics()->RecordUserMetricsAction(
-      enabled ? ash::UMA_STATUS_AREA_DISABLE_WIFI
-              : ash::UMA_STATUS_AREA_ENABLE_WIFI);
+  WmShell::Get()->RecordUserMetricsAction(
+      enabled ? UMA_STATUS_AREA_DISABLE_WIFI : UMA_STATUS_AREA_ENABLE_WIFI);
   handler->SetTechnologyEnabled(NetworkTypePattern::WiFi(), !enabled,
                                 chromeos::network_handler::ErrorCallback());
 }