Bug fix to toggle Network scanning indicator for WiFi

ash/common/system/chromeos/network/network_state_list_detailed_view.cc

Index: ash/common/system/chromeos/network/network_state_list_detailed_view.cc
diff --git a/ash/common/system/chromeos/network/network_state_list_detailed_view.cc b/ash/common/system/chromeos/network/network_state_list_detailed_view.cc
index 142bb4ec51f0995caf46001c60b4f67f099f9812..891dd1993293ee49430b92cb09e56a64ad9dcd3d 100644
--- a/ash/common/system/chromeos/network/network_state_list_detailed_view.cc
+++ b/ash/common/system/chromeos/network/network_state_list_detailed_view.cc
@@ -309,7 +309,7 @@ NetworkStateListDetailedView::NetworkStateListDetailedView(
     : NetworkDetailedView(owner),
       list_type_(list_type),
       login_(login),
-      wifi_scanning_(false),
+      prev_wifi_scanning_state_(false),

[jdufault, 2016/09/06 22:19:19]

Since you're already in this file, can you initialize all of these constant
values in the header?

       info_icon_(nullptr),
       button_wifi_(nullptr),
       button_mobile_(nullptr),
@@ -566,15 +566,15 @@ void NetworkStateListDetailedView::UpdateHeaderButtons() {
   if (proxy_settings_)
     proxy_settings_->SetEnabled(handler->DefaultNetwork() != nullptr);
 
-  if (list_type_ != LIST_TYPE_VPN) {
+  if (list_type_ != LIST_TYPE_VPN &&
+      !MaterialDesignController::IsSystemTrayMenuMaterial()) {
     // Update Wifi Scanning throbber.
     bool scanning =
         NetworkHandler::Get()->network_state_handler()->GetScanningByType(
             NetworkTypePattern::WiFi());
-    if (scanning != wifi_scanning_ &&
-        !MaterialDesignController::IsSystemTrayMenuMaterial()) {
-      wifi_scanning_ = scanning;
-      if (list_type_ != LIST_TYPE_VPN) {
+    if (scanning != prev_wifi_scanning_state_) {
+      prev_wifi_scanning_state_ = scanning;
+      if (scanning) {
         SetScanningStateForThrobberView(true);
 
         // Start animation on the |scanning_throbber_| indicator.