Add unit test for ArcBluetoothBridge and TypeConverter

components/arc/test/fake_arc_bridge_service.cc

Index: components/arc/test/fake_arc_bridge_service.cc
diff --git a/components/arc/test/fake_arc_bridge_service.cc b/components/arc/test/fake_arc_bridge_service.cc
index 64d17b03544f7921a7eae0926f8279751e33f64e..409c6a39afc1c347bde09c3319d0f8550f9095ab 100644
--- a/components/arc/test/fake_arc_bridge_service.cc
+++ b/components/arc/test/fake_arc_bridge_service.cc
@@ -6,8 +6,9 @@
 
 namespace arc {
 
-FakeArcBridgeService::FakeArcBridgeService() {
-}
+FakeArcBridgeService::FakeArcBridgeService()
+    : bluetooth_instance_(base::WrapUnique(new FakeBluetoothInstance())),
+      bluetooth_version_(2) {}
 
 FakeArcBridgeService::~FakeArcBridgeService() {
   SetStopped();
@@ -25,6 +26,14 @@ void FakeArcBridgeService::Shutdown() {
   SetStopped();
 }
 
+mojom::BluetoothInstance* FakeArcBridgeService::bluetooth_instance() {
+  return bluetooth_instance_.get();
+}
+
+int32_t FakeArcBridgeService::bluetooth_version() const {
+  return bluetooth_version_;
+}
+
 void FakeArcBridgeService::SetReady() {
   if (state() != State::READY)
     SetState(State::READY);