bluetooth: Return int8_t and use -128 for unknown tx power.

chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc

Index: chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
diff --git a/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc b/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
index 1350f0529278651eb192e3cd9fafd7ef115c1591..9769ab7246fef82bca6c8ab21de9782585e63536 100644
--- a/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
+++ b/chrome/browser/extensions/api/easy_unlock_private/easy_unlock_private_api.cc
@@ -68,6 +68,8 @@ namespace easy_unlock_private = api::easy_unlock_private;
 
 namespace {
 
+enum { kUnknownPower = 127 };
+
 static base::LazyInstance<BrowserContextKeyedAPIFactory<EasyUnlockPrivateAPI> >
     g_factory = LAZY_INSTANCE_INITIALIZER;
 
@@ -955,9 +957,14 @@ bool EasyUnlockPrivateGetConnectionInfoFunction::DoWork(
 void EasyUnlockPrivateGetConnectionInfoFunction::OnConnectionInfo(
     const device::BluetoothDevice::ConnectionInfo& connection_info) {
   std::unique_ptr<base::ListValue> results(new base::ListValue());
-  results->AppendInteger(connection_info.rssi);
-  results->AppendInteger(connection_info.transmit_power);
-  results->AppendInteger(connection_info.max_transmit_power);
+  results->AppendInteger(connection_info.rssi ? connection_info.rssi.value()
+                                              : kUnknownPower);
+  results->AppendInteger(connection_info.transmit_power
+                             ? connection_info.transmit_power.value()
+                             : kUnknownPower);
+  results->AppendInteger(connection_info.max_transmit_power
+                             ? connection_info.max_transmit_power.value()
+                             : kUnknownPower);
   SetResultList(std::move(results));
   SendResponse(true);
 }