[ash-md] Disables the Wi-Fi and Cellular toggles until the state changes

ash/common/system/chromeos/bluetooth/tray_bluetooth.cc

Index: ash/common/system/chromeos/bluetooth/tray_bluetooth.cc
diff --git a/ash/common/system/chromeos/bluetooth/tray_bluetooth.cc b/ash/common/system/chromeos/bluetooth/tray_bluetooth.cc
index a6a6c5e287a83ede7a2e41aefbffb223d0853f1a..03ad9b749022127cc1d56083b69e73de7a854589 100644
--- a/ash/common/system/chromeos/bluetooth/tray_bluetooth.cc
+++ b/ash/common/system/chromeos/bluetooth/tray_bluetooth.cc
@@ -266,8 +266,10 @@ class BluetoothDetailedView : public TrayDetailsView {
   void UpdateHeaderEntry() {
     bool is_bluetooth_enabled =
         WmShell::Get()->system_tray_delegate()->GetBluetoothEnabled();
-    if (toggle_)
-      toggle_->SetIsOn(is_bluetooth_enabled, false);
+    if (!toggle_)
+      return;
+    toggle_->SetEnabled(true);
+    toggle_->SetIsOn(is_bluetooth_enabled, false);
   }
 
   void UpdateDeviceScrollList() {
@@ -450,12 +452,16 @@ class BluetoothDetailedView : public TrayDetailsView {
 
   void HandleButtonPressed(views::Button* sender,
                            const ui::Event& event) override {
-    if (sender == toggle_)
+    if (sender == toggle_) {
+      // Disable the toggle to prevent bouncing. It will get re-enabled when

[tdanderson, 2017/02/28 16:30:03]

nit: Perhaps be a bit more specific with what is meant by 'bouncing' - maybe say
something like "In the event of multiple clicks within a short period of time,
helps to prevent a toggle button appearance becoming inconsistent with the async
operation of enabling/disabling Bluetooth" or similar but more condensed?

Ditto for the comment in network_list_md

[varkha, 2017/03/08 01:45:35]

Done (in network_list_md.cc).

+      // BluetoothDetailedView::Update() gets called.
+      toggle_->SetEnabled(false);
       WmShell::Get()->system_tray_delegate()->ToggleBluetooth();
-    else if (sender == settings_)
+    } else if (sender == settings_) {
       ShowSettings();
-    else
+    } else {
       NOTREACHED();
+    }
   }
 
   void CreateExtraTitleRowButtons() override {