BluetoothAdapterMac::LowEnergyDeviceUpdated() Implemented

device/bluetooth/bluetooth_adapter_mac.mm

Index: device/bluetooth/bluetooth_adapter_mac.mm
diff --git a/device/bluetooth/bluetooth_adapter_mac.mm b/device/bluetooth/bluetooth_adapter_mac.mm
index cf33939b61c4902c156f616a9e554e1fbabc6469..d7c6c41a54e99855d7e406f6f6f3ac4f717de335 100644
--- a/device/bluetooth/bluetooth_adapter_mac.mm
+++ b/device/bluetooth/bluetooth_adapter_mac.mm
@@ -402,11 +402,39 @@ void BluetoothAdapterMac::ClassicDeviceAdded(IOBluetoothDevice* device) {
                     DeviceAdded(this, devices_[device_address]));
 }
 
-// TODO(krstnmnlsn): Implement method. http://crbug.com/496987.
 void BluetoothAdapterMac::LowEnergyDeviceUpdated(
     CBPeripheral* peripheral,
     NSDictionary* advertisementData,
     int rssi) {
+  std::string device_address =
+      BluetoothLowEnergyDeviceMac::GetPeripheralHashAddress(peripheral);
+  BluetoothDevice*& device_reference = devices_[device_address];
+
+  if (!device_reference) {
+    // A new device has been found.
+    device_reference =
+        new BluetoothLowEnergyDeviceMac(peripheral, advertisementData, rssi);
+    FOR_EACH_OBSERVER(BluetoothAdapter::Observer, observers_,
+                      DeviceAdded(this, device_reference));
+    return;
+
+  } else {

[scheib, 2015/07/13 20:47:21]

OK, if you're going with early returns then we don't need 
} else { 
  if () {} 
}

Change it to just
if () {
  ... 
  return;
}

if () {
  ... 
  return;
}

...


(Also, no blank line after return;)

[krstnmnlsn, 2015/07/13 20:54:34]

Done.

+    if (static_cast<BluetoothLowEnergyDeviceMac*>(device_reference)
+            ->GetIdentifier() !=
+        BluetoothLowEnergyDeviceMac::GetPeripheralIdentifier(peripheral)) {
+      // Collision, two identifiers map to the same hash address.  With a 48 bit
+      // hash the probability of this occuring with 10,000 devices
+      // simultaneously present is 1e-6 (see
+      // https://en.wikipedia.org/wiki/Birthday_problem#Probability_table).  We
+      // ignore the second device by returning.
+      return;
+    }
+    // A device has an update.
+    static_cast<BluetoothLowEnergyDeviceMac*>(device_reference)
+        ->Update(peripheral, advertisementData, rssi);
+    FOR_EACH_OBSERVER(BluetoothAdapter::Observer, observers_,
+                      DeviceChanged(this, device_reference));
+  }
 }
 
 void BluetoothAdapterMac::RemoveTimedOutDevices() {