device/bluetooth/bluez: add discoverable timeout adapter property

device/bluetooth/bluetooth_adapter.h

Index: device/bluetooth/bluetooth_adapter.h
diff --git a/device/bluetooth/bluetooth_adapter.h b/device/bluetooth/bluetooth_adapter.h
index 87f18ef2c3ef6542594f4ced9808d836dca86267..6137bd4a64a2a9e20d8938565f2a4606217b8f64 100644
--- a/device/bluetooth/bluetooth_adapter.h
+++ b/device/bluetooth/bluetooth_adapter.h
@@ -310,6 +310,12 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapter
                                const base::Closure& callback,
                                const ErrorCallback& error_callback) = 0;
 
+#if defined(OS_CHROMEOS) || defined(OS_LINUX)
+  // Returns the timeout after which the adapter exits discoverable mode in
+  // seconds, or zero if the adapter is always discoverable.
+  virtual uint32_t GetDiscoverableTimeout() const = 0;

[rkc, 2016/06/23 23:53:05]

Is this something other platforms may need or is it something we are doing
exclusively for compatibility with ARC++?

+#endif
+
   // Indicates whether the adapter is currently discovering new devices.
   virtual bool IsDiscovering() const = 0;