arc: bluetooth: Fix reading RSSI for connected devices

Android use ReadRemoteRssi() to get the RSSI value for a connection.
Currently we are using GetInquiryRSSI(), which cannot get the correct
RSSI value for a connected device, and makes some Android apps unhappy.
This change uses GetConnectionInfo() instead.

BUG=b:147787450
TEST=Manually test with nRF and Fitbit. nRF can read RSSI value
correctly; Firmware update of Fitbit works well now.

Change-Id: I0dc13f58f430954772551165009d5ea7f26445c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2004429
Commit-Queue: Jie Jiang <jiejiang@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736219}

chrome/browser/chromeos/arc/bluetooth/arc_bluetooth_bridge.cc

@@ -412,6 +412,12 @@ std::vector<uint8_t> MakeCCCDValue(uint8_t value) {
   return {value, 0};
 }
 
+void SendRssiOnGetConnectionInfoDone(
+    arc::ArcBluetoothBridge::ReadRemoteRssiCallback callback,
+    const device::BluetoothDevice::ConnectionInfo& conn_info) {
+  std::move(callback).Run(conn_info.rssi);
+}
+
 }  // namespace
 
 namespace arc {
@@ -1756,8 +1762,14 @@ void ArcBluetoothBridge::ReadRemoteRssi(mojom::BluetoothAddressPtr remote_addr,
     std::move(callback).Run(mojom::kUnknownPower);
     return;
   }
-  std::move(callback).Run(
-      device->GetInquiryRSSI().value_or(mojom::kUnknownPower));
+
+  if (device->IsConnected()) {
+    device->GetConnectionInfo(base::AdaptCallbackForRepeating(
+        base::BindOnce(&SendRssiOnGetConnectionInfoDone, std::move(callback))));
+  } else {
+    std::move(callback).Run(
+        device->GetInquiryRSSI().value_or(mojom::kUnknownPower));
+  }
 }
 
 void ArcBluetoothBridge::OpenBluetoothSocket(