arc: bluetooth: Implement Gatt notify

components/arc/common/bluetooth.mojom

Index: components/arc/common/bluetooth.mojom
diff --git a/components/arc/common/bluetooth.mojom b/components/arc/common/bluetooth.mojom
index 2017ee0434af0761cad5f0d4ec90d34b68c8a2db..67bc7ff87234b306809d13909d18f71f7916b729 100644
--- a/components/arc/common/bluetooth.mojom
+++ b/components/arc/common/bluetooth.mojom
@@ -321,4 +321,9 @@ interface BluetoothInstance {
                                       uint16 end_handle);
   [MinVersion=1] OnServicesAdded@12(BluetoothAddress remote_addr,
                                     array<BluetoothGattDBElement> db);
+  [MinVersion=2] OnGattNotify@13(BluetoothAddress remote_addr,
+                                 BluetoothGattServiceID service_id,
+                                 BluetoothGattID char_id,
+                                 bool is_notify,

[ortuno, 2016/06/21 23:23:06]

What purpose does is_notify serve? When is it true and when is it false?

It makes me really sad that there is not a single comment in all these
functions. This code is going to be really hard to maintain...

[puthik_chromium, 2016/06/23 02:53:34]

It's map to is_notify in here. It should be true for notify and false for
indicate. Now it is always true.
[1]
https://source.android.com/devices/halref/structbtgatt__notify__params__t.html

[ortuno, 2016/06/23 14:29:38]

I see. Does this have to match the android implementation? Otherwise I would use
an enum. We usually only use bools if the variable actually means false.

[puthik_chromium, 2016/06/23 18:36:30]

I would prefer to match it to android. It will make life easier when we need to
upgrade to Android N

+                                 array<uint8> value);
 };