Add signal strength indicator icon to WebBluetooth chooser on non-Mac desktops

content/browser/bluetooth/bluetooth_device_chooser_controller.cc

Index: content/browser/bluetooth/bluetooth_device_chooser_controller.cc
diff --git a/content/browser/bluetooth/bluetooth_device_chooser_controller.cc b/content/browser/bluetooth/bluetooth_device_chooser_controller.cc
index b2d8792f0c4a5fd5ddccd1b9594b719793ec41df..38f42438be0a581a0243b0aa0619bbd892a72238 100644
--- a/content/browser/bluetooth/bluetooth_device_chooser_controller.cc
+++ b/content/browser/bluetooth/bluetooth_device_chooser_controller.cc
@@ -339,14 +339,14 @@ void BluetoothDeviceChooserController::GetDevice(
 void BluetoothDeviceChooserController::AddFilteredDevice(
     const device::BluetoothDevice& device) {
   if (chooser_.get() && MatchesFilters(device, options_->filters)) {
+    base::Optional<int8_t> rssi = device.GetInquiryRSSI();
     chooser_->AddOrUpdateDevice(
         device.GetAddress(),
         // TODO(https://crbug.com/634366): Update device's name when necessary.
         false /* should_update_name */, device.GetNameForDisplay(),
         // TODO(http://crbug.com/543466): Show connection and paired status.
         false /* is_gatt_connected */, false /* is_paired */,
-        // TODO(http://crbug.com/629689): Add signal strength indicator.
-        nullptr /* rssi */);
+        rssi ? &(rssi.value()) : nullptr);

[msw, 2016/08/12 23:08:49]

Just pass a plain int8_t, instead of a const pointer? Nevermind if there's no
reasonable value that could mean "signal strength not available".

[juncai, 2016/08/15 21:53:20]

Some context:
We discussed this at:
https://codereview.chromium.org/2210873003/
And it seems that the range of int8_t are all possible values for RSSI. So we
chose using a pointer here.

   }
 }