Bluetooth: macOS: DidModifyServices can happens while scanning

device/bluetooth/bluetooth_low_energy_device_mac.mm

Index: device/bluetooth/bluetooth_low_energy_device_mac.mm
diff --git a/device/bluetooth/bluetooth_low_energy_device_mac.mm b/device/bluetooth/bluetooth_low_energy_device_mac.mm
index b5777bed5d8de949320ac3022b50065c2ec2c682..3bd2dc62692591d2793220fa405e3d6641ab2475 100644
--- a/device/bluetooth/bluetooth_low_energy_device_mac.mm
+++ b/device/bluetooth/bluetooth_low_energy_device_mac.mm
@@ -254,6 +254,13 @@ void BluetoothLowEnergyDeviceMac::DidDiscoverCharacteristics(
     // Don't create characteristics if the device disconnected.
     return;
   }
+  if (IsGattServicesDiscoveryComplete()) {
+    // This should never happens, just in case it happens with a device,

[scheib, 2017/04/18 04:43:21]

"never happen"

[jlebel, 2017/04/29 22:08:07]

Done.

+    // this notification should be ignored.
+    VLOG(1) << *this
+            << ": Discovery complete, ignoring DidDiscoverCharacteristics.";
+    return;
+  }
 
   BluetoothRemoteGattServiceMac* gatt_service =
       GetBluetoothRemoteGattService(cb_service);
@@ -325,6 +332,13 @@ void BluetoothLowEnergyDeviceMac::DidDiscoverDescriptors(
     // Don't discover descriptors if the device disconnected.
     return;
   }
+  if (IsGattServicesDiscoveryComplete()) {
+    // This should never happens, just in case it happens with a device,

[scheib, 2017/04/18 04:43:21]

ditto

[jlebel, 2017/04/29 22:08:07]

Done.

+    // this notification should be ignored.
+    VLOG(1) << *this
+            << ": Discovery complete, ignoring DidDiscoverDescriptors.";
+    return;
+  }
   BluetoothRemoteGattServiceMac* gatt_service =
       GetBluetoothRemoteGattService(cb_characteristic.service);
   DCHECK(gatt_service);
@@ -360,6 +374,7 @@ void BluetoothLowEnergyDeviceMac::DiscoverPrimaryServices() {
 }
 
 void BluetoothLowEnergyDeviceMac::SendNotificationIfDiscoveryComplete() {
+  DCHECK(!IsGattServicesDiscoveryComplete());
   // Notify when all services have been discovered.
   bool discovery_complete =
       discovery_pending_count_ == 0 &&