Remove "Searching for Wi-Fi networks..." message.

ash/system/network/network_state_list_detailed_view.cc

Index: ash/system/network/network_state_list_detailed_view.cc
diff --git a/ash/system/network/network_state_list_detailed_view.cc b/ash/system/network/network_state_list_detailed_view.cc
index 9bb2996a76d0edef330e9745a9714a3be2509109..9f591ac295a2cba9e2077b7e08e6dcd60699db15 100644
--- a/ash/system/network/network_state_list_detailed_view.cc
+++ b/ash/system/network/network_state_list_detailed_view.cc
@@ -370,13 +370,10 @@ void NetworkStateListDetailedView::UpdateHeaderButtons() {
         nullptr);
   }
   if (list_type_ != LIST_TYPE_VPN) {
-    bool scanning =
+    const bool scanning =
         NetworkHandler::Get()->network_state_handler()->GetScanningByType(
             NetworkTypePattern::WiFi());
     ShowProgress(-1, scanning);
-    info_button_->SetTooltipText(l10n_util::GetStringUTF16(
-        scanning ? IDS_ASH_STATUS_TRAY_WIFI_SCANNING_MESSAGE
-                 : IDS_ASH_STATUS_TRAY_NETWORK_INFO));
   }
 }