cros: Clean up TrayBluetoothHelper todos

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

Index: ash/common/system/chromeos/bluetooth/tray_bluetooth.h
diff --git a/ash/common/system/chromeos/bluetooth/tray_bluetooth.h b/ash/common/system/chromeos/bluetooth/tray_bluetooth.h
index 379671c02018233daecbeb283a873baa33667f4f..d6d73d880424e85d0a4392a6998b31683cac534c 100644
--- a/ash/common/system/chromeos/bluetooth/tray_bluetooth.h
+++ b/ash/common/system/chromeos/bluetooth/tray_bluetooth.h
@@ -15,6 +15,11 @@ class BluetoothDefaultView;
 class BluetoothDetailedView;
 }
 
+// Bluetooth section in the main system tray menu. Contains:
+// * Toggle to turn Bluetooth on and off
+// * Gear icon that takes the user to the web ui settings
+// * List of paired devices
+// * List of unpaired devices
 class TrayBluetooth : public SystemTrayItem, public BluetoothObserver {
  public:
   explicit TrayBluetooth(SystemTray* system_tray);